WO1996000920A1

WO1996000920A1 - Optoelectronic package and bidirectional optical transceiver for use therein

Info

Publication number: WO1996000920A1
Application number: PCT/US1995/008402
Authority: WO
Inventors: Robert Addison Boudreau; Terry Patrick Bowen; Ervin Herbert Mueller; Dale Dennis Murray; Narinder Kapany
Original assignee: The Whitaker Corporation
Priority date: 1994-06-30
Filing date: 1995-06-29
Publication date: 1996-01-11

Abstract

An optoelectronic package (1) includes an optoelectronic module, such as a hermetically sealed bidirectional optical transceiver (3) including an optical fiber pigtail (6) extending therefrom, a ferrule (9) receiving an end of the optical fiber pigtail (6), and a split sleeve connector (11) housing the ferrule (9). The hermetically sealed bidirectional optical transceiver (3) is mounted on a support (5) and an acute angle η with respect to the connector (11). Thus, the optical fiber pigtail (6) is angled between the hermetically sealed bidirectional optical transceiver (3) and the ferrule (9) to provide for strain relief in the optical fiber pigtail (6). Further, the hermetically sealed bidirectional optical transceiver (3) for use in the optoelectronic package (1) includes a first optical fiber (21) for transmitting optical signals therethrough, having an acutely angled endwall, a second optical fiber (27) for transmitting and receiving optical signals therethrough, having an endwall proximate to the acutely angled endwall of the first optical fiber (21), a light source (19) for generating light of a first wavelength, and a detector (25) for detecting light of a second wavelength, different from the first wavelength. The acutely angled endwall of either the first or second optical fiber reflects at least a portion of light of the second wavelength, passing from the second optical fiber (27) to the detector (25), and passes at least a portion of light of the first wavelength to the second optical fiber (27). More preferably, the acutely angled endwall of either the first or second optical fiber includes a dichroic coating.

Description

OPTOELECTRONIC PACKAGE

AND BIDIRECTIONAL

OPTICAL TRANSCEIVER FOR USE THEREIN

FIELD OF THE INVENTION

The present invention relates to a novel optoelectronic package and bidirectional optical transceiver for use therein, the entire module being usable in a bidirectional optical fiber network. More particularly, the present invention relates to a type of optoelectronic package which includes any type of optoelectronic device such as a hermetically sealed optical transceiver, including an optical fiber pigtail extending therefrom; a connector including a ferrule receiving an end of the optical fiber pigtail and a connector sleeve housing the ferrule; and an external casing housing the optoelectronic device and at least a portion of the connector. The hermetically sealed optical transceiver is mounted on a support, with the mounting being preferably at an acute angle with respect to the split sleeve connector, and/or with the optical fiber pigtail being angled between the hermetically sealed optical transceiver and the ferrule to provide strain relief in the optical fiber pigtail. Further, the present invention is related to a bidirectional optical transmitter/receiver (transceiver) for use in the aforementioned optoelectronic package.

BACKGROUND OF THE INVENTION Optoelectronic packaging (OEP) is the engineering science of how to provide protection, support, and connection to optical chips, such as semiconductor lasers, and their associated electrical chips so that the chips can provide their useful function. Optoelectronic packaging is analogous to electrical packing, except that it is complicated by the addition of the considerable restraints associated with handling optics. The restraints include precise positioning of optical elements within the package and restrictions on where the optical paths can be placed. As telecommunications, data, and video services require greater bandwidth and higher speed transmission, there will be an ever-increasing need for OEP. Originally, when semiconductor lasers were introduced into long-haul telecommunications, their packages were largely based on handcrafting, and costs were high. Long-haul optical telecommunication networks employ high performance optoelectronic components, such as lasers and photo detectors, which are coupled optical fibers. Expansion of the optical fiber network into the local loop requires several optoelectronic and fiber components for each customer, the cost of which cannot be shared among thousands of customers as in long-haul optical networks. This situation imposes significant demands with regard to obtaining optoelectronic components that could be manufactured at a low cost.

These optoelectronics tend to be expensive because many assembly operations are still handcrafted and many packages are built as packages within packages. The package-within-package situation arises from the use of transistor outline (TO) cans or headers. A TO can is used to provide a hermetic capsule to protect a laser or detector chip while allowing light to pass through a tiny window. Tiny wire bonds connect to the leads that feed through the bottom of the can. Manufacturers of laser and detector chips frequently sell their chips and these cans, which are then used in larger packages where optical elements such as fibers, lenses, and electronics are added. The most expensive part . of OEP is the optical alignment. The optical-alignment position tolerance for multimode optical interconnections is about 5-10 micrometers (μm) ; for single-mode interconnections, it is about lμm. If an optical fiber is lensed, it can achieve a higher coupling efficiency at the expense of even more sensitivity to position misalignment. However, applications requiring high speed data transmission of about 2 gigabits per second and above require a single-mode fiber, and a single-mode fiber may further be needed if the transmission distance is long. Packages requiring optical alignments with single-mode fibers are the most expensive.

Optical alignments can be performed both actively and passively. An active alignment is where the laser detector device is operated and a fiber is manipulated in front of it until the optical signal is peaked. The fiber is then bonded to the package. A passive alignment is where the alignment position of the fiber is determined by a mechanical or optical reference feature on the device being aligned and the fiber is bonded into position without the operating device. The passive alignment is intrinsically faster and simpler but requires a special package design. Active alignments are the most common and are required for all packages based on TO cans since there is no reference to locate the optical device within the device.

In several instances, it has been recognized that when manufacturing with OEP, packaging costs comprise from 70-80% of total component cost. Further, reliability studies show most failure modes are package related. Also, new kinds of optoelectronics are being developed that have no means of being packaged. Still further, there is a need to be able to integrate optoelectronics with devices made of differing materials. Therefore, demand for new and useful, and low cost optoelectronic packaging and optoelectronic packages are now at an all-time high. SUMMARY OF THE INVENTION

Accordingly, it is a primary object of the present invention to provide a low cost, compact, connectorized optoelectronic package. It is a further object of the present invention to provide a low cost optoelectronic package utilizing optoelectronic elements such as a compact bidirectional optical transceiver, a compact laser or a compact detector. It is a still further object of the present invention to provide an optoelectronic package wherein a compact bidirectional optical transceiver, compact laser or compact detector can be passively aligned.

It is yet another object of the present invention to provide an integrated optical transceiver which may be used in an optoelectronic package and further can be used in an optical network for bidirectional optical message and signal transmission which includes, integrated on a common substrate, an optical fiber with an acutely angled endwall, a light source, and an optical detector.

It is yet a further object of the present invention to provide an optoelectronic package utilizing silicon waferboard technology (SWT) for formation of an optoelectronic component featuring optoelectronic integration for small size and high functionality permitting active or passive alignment of the optical components within the package.

It is still yet a further object of the present invention to provide a bidirectional optical transceiver for use in an optoelectronic package which includes at least one optical fiber with an acutely angled endwall which acts as an optical beamsplitter.

The objects of the invention are fulfilled by providing an optoelectronic package comprising: an optoelectronic device, including an optical fiber pigtail extending therefrom; a connector including, a ferrule receiving an end of said optical fiber pigtail, and a connector sleeve housing said ferrule; and an external casing housing the optoelectronic device and at least a portion of the connector.

The objects of the invention are further fulfilled by providing an optoelectronic package wherein the optoelectronic device is a hermetically sealed optoelectronic circuit, which is mounted on a support, at an acute angle with respect to the split sleeve connector to provide for strain relief in the optical fiber pigtail. The objects of the present invention are still further fulfilled by providing an optoelectronic package, wherein the optical fiber pigtail is angled between the hermetically sealed optical transceiver, or other optoelectronic device, and the ferrule to provide for strain relief from the optical fiber pigtail.

The objects are yet still further fulfilled by providing a hermetically sealed bidirectional optical transceiver for use in an optoelectronic package including a ferrule and a connector, housing the ferrule, mounted within the optoelectronic package, the hermetically sealed bidirectional optical transceiver comprising: first optical fiber, for transmitting optical signals therethrough, having an acutely angled endwall; second optical fiber, for transmitting and receiving optical signals therethrough, having an endwall proximate to the acutely angled endwall of the first optical fiber; light source for generating outgoing light; and detector for detecting incoming light, wherein the acutely angled endwall of the first optical fiber reflects at least a portion of the incoming light, passing from the second optical fiber to the detector, and passes at least a portion of the outgoing light to the second optical fiber. Advantages of the optoelectronic package and hermetically sealed bidirectional optical transceiver for use in the optoelectronic package of the present invention include: (1) a device which is small in size and is therefore compact; (2) a device which can be constructed inexpensively and simply since silicon waferboard technology (SWT) may be employed, thereby eliminating parts because of the use of etched mechanical features and patterned depositions which replace separate submounts, wire bonds, standoffs and fiberblocks required in conventional devices and which do not utilize transistor outline (TO) cans or headers for the laser detector components for example; (3) a device which advantageously allows for passive-optical alignment assembly suitable for both multimode and single-mode fibers; (4) a device in which the electrical input/output from the connector module is flexible in design and can be specified by the customer; and (5) a device which utilizes minimal components by utilizing angled endwalls of at least one optical fiber for beamsplitting purposes thereby removing any need to employ conventional and expensively beamsplitting prisms or mirrors; (6) an optoelectronic package which can house actual optoelectronic elements such as lasers and transceivers, made small by the use of SWT technology. These and other objects of the present application will become more readily apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and - 1 -

scope of the i; ention will become apparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention and wherein:

Fig. l is a perspective view of an embodiment of the optoelectronic package of the present invention;

Fig. 2 is a side view of the optoelectronic package of Fig. 1;

Fig. 3 is a perspective view of an embodiment of the hermetically sealed bidirectional optical transceiver for use in the optoelectronic package of Fig. 1;

Fig. 4 is a cutaway view illustrating the bidirectional beamsplitting junction (or beamsplitter) of optical fibers within the hermetically sealed directional optical transceiver of Fig. 3; and

Fig. 5 is a top plan view, cut along the line A-A of Fig. 4, of a portion of the bidirectional optical transceiver of Fig. 3 for use in the optoelectronic package.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Fig. 1 illustrates an optoelectronic package 1 of a first embodiment of the present invention. An optoelectronic device, which may be a compact laser, a compact detector or a hermetically sealed bidirectional optical transceiver 3, is shown in Fig. 1. The specific use of a hermetically sealed bidirectional optical transceiver 3 will be further described in detail with regard to Fig. 4 of the present application. Attached to the optoelectronic device 3 is an optical fiber 6. This optical fiber 6 may or may not be preattached to the optoelectronic device 3. If it is preattached or bonded to the optoelectronic device (such as a hermetically sealed bidirectional optical transceiver) 3, it can be pigtailed, meaning the fiber hangs out of the optoelectronic device. The optical fiber 6 is preferably bent at an angle as illustrated by element 7 in Fig. 1. The optical fiber 6 is further preferably angled based on the fact that the optoelectronic device 3 can be mounted by soldering for example, or bonded with an epoxy, on a submount 5 at an angle as shown in 7 in Fig. 1. This angle, 7, and the angle in the optical fiber as shown by element 7 provides some stress or strain relief to the optical fiber itself. The optical fiber 6 is connected or attached to ferrule 9. The ferrule acts as a mounting aid for the optical fiber 6 and is the same as is used is known optical fiber connectors. In one preferred embodiment, the ferrule is cylindrical and is a spring loaded ferrule as is shown by 9 in Fig. 1.

A connector sleeve 11 houses the ferrule 9. Preferably, this connector is a split sleeve connector which contracts on the ferrule 9 to hold it in place. The nature of the electrical input/output connections from the connector module (including connector sleeve 11 and ferrule 9) is flexible in design and can be specified by the customer. Electrical signals pass from the internal submodule 3 (the optoelectronic device) by first passing through an electrical vias at the base of the internal submodule 3 as will be discussed later with regard to Fig. 4 of the present application.

Further, as shown in Fig. 1, the connector assembly itself including split sleeve connector 11, further includes supports 13 which are attached to a base 15 which comprises part of the external casing of the optoelectronic package 1. The support 5 for the - 9 -

hermetically sealed optical transceiver 3 is also mounted to the base 15. The aforementioned mounting may be achieved via soldering, or an epoxy may be used. Finally, an external cover or casing 17 is connected to the base, and houses the optoelectronic device or submodule 3 (such as a hermetically sealed bidirectional optical transceiver 3) , the optical fiber 6, the ferrule 9, and at least a portion of the connector 11. This casing 17 may be plastic or metal for example. Thus, an optoelectronic package or connector is created which can house any type of pre-formed submodule 3 (such as a compact laser, a compact detector or an optical transceiver, separately formed and passively aligned, by a technology such as SWT) . Thereby, the inexpensive optoelectronic package 1 is created which houses its own optoelectronic submodule 3 (unlike known connector modules which had connectors bonded to the side of the optoelectronic package itself and had lasers or other optoelectronic devices external thereto) . Fig. 2 illustrates a side cutaway view of the optoelectronic package 1. Fig. 2 shows the optoelectronic submodule, the hermetically sealed bidirectional optical transceiver 3, with the optical fiber 6 extending therefrom, mounted on the support 5. The optical fiber 6 is preferably a silica or glass fiber, but may be plastic. The fiber 6 must be of a consistent diameter with low loss and high precision so it can be passively aligned in a V-groove as will be explained later. Fig. 2 further illustrates the ferrule 9 receiving the optical fiber 6, and being mounted in split sleeve connector 11. Finally, supports 13 are shown for mounting the connector 11 to the base 15. The external casing of the optoelectronic package 1 is further illustrated as including the base 15 and an external cover 17, connected to the base 15, housing the optoelectronic submodule (hermetically sealed bidirectional optical transceiver 3) , the optical fiber 6, the ferrule 9, and at least a portion of the connector 11. Both Figs. 1 and 2 have been drawn to scale and a line designating the equivalent of one scaled centimeter is separately shown with regard to each of the Figs 1 and 2.

Fig. 3 illustrates a type of optoelectronic submodule, a hermetically sealed bidirectional optical transceiver 3, for use in the optoelectronic package 1 of the Fig. 1. The hermetically sealed bidirectional optical transceiver 3 includes a light source 19 mounted to a substrate 29. The light source 19 may be laser, such as a semiconductor laser, or a light emitting diode (LED) . The light source is for generating outgoing optical signals, such as light of a first wavelength λ,.

A first optical fiber 21 is connected to the light source 19. The optical fiber 21 is for transmitting optical signals therethrough. The optical fiber 21 is mounted in a V-groove in substrate 29 as will be later described. The optical fiber 21 then passes to a silicon bridge 23, and is also mounted in an inverse V- groove in silicon bridge 23 as will be described later. Mounted within the silicon bridge is a beamsplitting junction 35 as will further be described with regard to Fig. 4 of the present application. Mounted over a hole pre-formed in the silicon bridge 23 is a detector 25 (which is a light detector or photo detector) , for detecting incoming optical signals, such as optical signals of a second wavelength λ₂.

Extending from silicon bridge 23 is a second optical fiber 27 (also formed in the aforementioned V- grooves) , for outputting outgoing optical signals, such as those of a first wavelength \, from light source 19, and for providing incoming optical signals, such as those of a second wavelength λ₂ to optical detector 25. An electric vias 31 is further shown in Fig. 4, below substrate 29. The electrical vias or contacts 31 abuts support 5 as shown in Fig. 1, and electrical signals pass to the internal submodule 3, such as the hermetically sealed bidirectional transceiver 3, and to the connector module including connector 11, by first passing from an external power source through connectors or fingers 32 (of Fig. 1) and through electrical vias 31 at the base of the substrate 29. The vias 31 are merely electrical contacts which penetrate silicon substrate 19.

Finally, the optical transceiver 3 as shown in Fig. 3 is hermetically sealed by hermetic cover 33 which may preferably be formed of silicon, but which can also be metal or glass. Further, plastic can be used to form a pseudo hermetic seal (which may have a slow leak, which may not have an effect on the device over its usable life) . The cover 33 may be sealed around its perimeter using solder of glass frit to provide hermeticity and further includes a vent hole that can be tipped off to capture an inert atmosphere, within if desired.

Fig. 4 is a cutaway view of the transceiver 3 of Fig. 3, and illustrates the beamsplitting aspect of the optical transceiver 3, which utilizes acutely angled endwalls of the optical fibers to pass outgoing beams, preferably of a first wavelength λ, and to reflect incoming beams, preferably of a second wavelength λ₂.

As shown in Fig. 4, the beamsplitter or beamsplitting junction 35 is housed by a silicon bridge 23. The silicon bridge 23 incudes an inverse V-groove 38, in which fibers 21 and 27 forming the beamsplitter 35, are mounted. The bridge 23 includes a hole 50. Above the hole 50 is a detector 25 mounted or bonded on bridge 23, such that the bridge 23 holds the detector 25 above and directly over beamsplitter 35. Finally, as illustrated in Fig. 5, the bridge 23 is then mounted on substrate 29 using mounting or alignment blocks 40.

The beamsplitting junction 35 includes a first optical fiber 21 for transmitting outgoing optical signals, preferably of a first wavelength λ₁, output from light source 19. The endwall of a first optical fiber 21 is angled at an acute angle, ranging from 30°-60° and preferably 45°, with respect to the substrate 29. In one preferred embodiment, this acutely angled endwall of the first optical fiber 21 is coated with a dichroic coating 41 composed of a multilayer dielectric coating of varying thicknesses such as ZnS, Al₂0₃ or Ti0₂ for passing at least a portion of light of a first wavelength λ and for deflecting at least a portion of light of a second wavelength λ₂.

The second optical fiber 27 also includes an endwall 39 which is acutely angled. In one preferred embodiment, the second optical fiber 27 is acutely angled, the acute angle of optical fiber 27 being complementary to the acute endwall of optical fiber 21, as is shown in Fig. 5. This acutely angled endwall 39 of optical fiber 27 also ranges from 30°-60°, and is preferably 45°.

Finally, Fig. 5 illustrates a top plan view of a portion of the hermetically sealed bidirectional optical transceiver 3 for use in the optoelectronic package 1 of the present application, cut along section A-A of Fig. 4. Fig. 5 illustrates an optical fiber 21, silicon bridge 23, and detector 25, along with substrate or mounting block 29. Fig. 5 further illustrates a V- shaped groove 36 and 38. In the V-shaped grooves 36 and 38 are mounted optical fibers 21 and 27. The V-shaped groove 38 for mounting optical fibers 21 and 27 (which is an inverse V-groove) is included on bridge 23. Further, a similar V-groove for mounting optical fiber 21 can be included in at least a portion of an additional mounting substrate near ferrule 9, to aid in the alignment of the optical fiber 21 with the ferrule 9 housed within connector 11.

Also, as illustrated in Fig. 5, is the hole 50. This hole 50 is preferably pattern etched during the formation of bridge 23. As can be seen from Fig. 5, the detector 25 is mounted over hole 50, which is aligned with the beamsplitter 35 to receive the reflected incoming light. Operation of the Optical Transceiver 3 for use in the optoelectronic package l of the present application will now be described. As previously indicated, Fig. 4 illustrates a beamsplitting junction 35. Two optical fibers 21 and 27 have abutting endwalls 37 and 39, respectively, which are proximate to each other. At least one of the endwalls 37 and 39 is formed at an angel a as is shown in Fig. 5. Preferably, the abutting endwalls of 37 and 39 are each at an angle other than that perpendicular (30°- 60°) to the direction of optical signals having wavelengths λ, and λ₂, which represent an outgoing signal and an incoming signal, respectively in one preferred embodiment of the present application. More preferably, at least one of the endwalls 37 and 39 is angled at an acute angle with respect to the substrate 29, which preferably can be 45°. Still more preferably, the other of the endwalls 37 and 39 is also angled at an acute angle α as shown in Fig. 5, which is complementary to the acute angle of the other endwall 37 and 39, which may also be 45°. As is further illustrated in Fig. 1, the optical outgoing signal generated by light source 19, of a wavelength λ_x for example, is split into a first component 43 which passes through the junction 35, and into a second component 45. The incoming optical signal having a wavelength λ₂ differing from the generated wavelength λj for example, is also split into a first portion 47 which is reflected at the junction 35, and a second component 49 which passes through the junction 35. The abutting endwalls 37 and 39, or at least the endwall which is acutely angled, may additionally include coatings of a dichroic substance ^* (or dielectric) , so as to control the direction of light on a wavelength-sensitive basis. In other words, the abutting endwalls 37 or 39 of the optical fiber, or alternately at least one endwall of one optical fiber, can be coated with a dichroic substance which acts to pass at least a portion of light of a first wavelength λ_[ (i.e. outgoing light is generated by a light source 19) and which acts to reflect at least a portion of light of a second wavelength (i.e. incoming light generated by a light source of a remotely located optical transceiver) .

In another preferred embodiment, the incoming and outgoing light is of the same wavelength. This can occur in a situation where the speed of the data being transmitted is below 300 megabits/second, or more

'preferably, below 155 megabits/second. If this is the case, then the dichroic or dielectric coating 41 is unnecessary and can be removed. All that is necessary is the aforementioned acutely angled endwalls 37 and 39 of fibers 21 and 27, for passing at least a portion

(preferably 50%) of outgoing light from laser 19 and for reflecting at least a portion (preferably 50%) of incoming light to detector 25. In high speed applications, two separate wavelengths are used to prevent noise.

The endwalls 37 and 39 of the optical fibers 21 and

27 may be coated with a dichroic substance as previously mentioned. The dichroic substance as illustrated by 41 in Fig. 4, allows for the passing of at least a portion of light beams less than or equal to a first wavelength

(for example, less than or equal to 1.3μm as generated by light source 19) , and for deflecting at least a portion of light beams greater than or equal to a second wavelength (for example, greater than or equal to 1.55μm as generated by a light source of a remote transceiver) , the first and second wavelengths being dependent upon the dichroic substance used. However, it should be noted that the aforementioned wavelengths are merely exemplary and are not limitative of the present invention. The angle of the abutting or at least proximate endwalls 37 and 39 of optical fibers 21 and 27 is constructed such that a significant component (preferably 50% of greater) of the incoming optical signal having wavelength λ,, for example, is reflected, as shown by component 47, through hole 50 to detector 25. Thus, an insignificant component of the incoming optical signal having a wavelength λ₂ for example, as shown by element 49 in Fig. 4 passes through the beamsplitting junction 35 from optical fiber 23 to optical fiber 21. The angle of the abutting or at least proximate endwalls 37 and 39 is further constructed such that a significant component (preferably 50% or greater) of the outgoing optical signal having a wavelength λ, for example, is transmitted past the junction 35 and to optical fiber 23. This component is shown by element 43 in Fig. 4. Thus, an insignificant component as shown by element 45 in Fig. 4 of the outgoing optical signal, having a wavelength λ_t for example, is reflected in a direction away from the optical detector. Again, the angle of at least one of endwalls 37 and 39 is preferably an acute of 30°- 60°angle and is more preferably about 45°. The angles of the endwalls of the first optical fiber 21 and the second optical fiber 27 are each preferably acutely angled (preferably at 45°) in an approximately complementary fashion. Manufacture of the optoelectronic module 3 of the package 1 is preferably done using silicone waferboard technology (SWT) and a hermetic sealant, prior to encapsulation of the entire optoelectronic package. By using SWT, this avoids the packaging-within-packaging approach of the TO cans and places semiconductor and optical components such as elements 19, 23 and 25 of Figs. 3 and 4 on a common silicone substrate such as 29 of Figs. 3 and 5 in a manner similar to multi-chip module construction. Many significant advantages accrue from this approach. Firstly, it is possible to chemically etch the silicon surface to a mechanical tolerance of 0.5μm, allowing for passive-optical alignment assembly suitable for both multimode and single-mode optical fibers. The V-grooves 36 and 38 can be etched in substrate 29 and bridge 23 respectively. Further, the hole 50 can be precisely etched in bridge 23 prior to bonding detector 25 to bridge 23.

Further, parts are eliminated since etched mechanical features and patterned depositions replace separate submounts, wire bond standoffs, and fiber blocks common in conventional packages. Also, some electronics can be incorporated in the silicon substrate using conventional integrated circuit processing techniques.

Utilizing SWT, optics and electronics can be combined to form the higher-level functional unit (the optoelectronic module 3 such as a compact laser, a compact detector or a transceiver) featuring optoelectronic integration for small size and high functionality permitting active or passive alignment of the optical components. Thus, the entire hermetically sealed bidirectional optical transceiver 3, for example, for use in the optoelectronic package 1 of the present invention, along with the above-described components, may be constructed using conventional silicone wafer technology. The components such as the light source 19 and the silicone bridge 23 can be soldered or epoxy can be used to mount them to the substrate 29. Similarly, the optical fibers 21 and 27 are attached to the substrate 29 in a V-groove such as 36 shown in Fig. 5 and an inverse V-groove 38 of Fig. 5. Alignment pedestals 40 (Fig. 5) are used to align bridge 23 and similarly pedestals 34 (Fig. 5) are used to align laser 34. The use of the aforementioned SWT technology including mounting of fibers in V-grooves and alignment of optoelectronic devices using pedestals to align bridge 23 and laser 19 are discussed in U.S.P. 5,163,108 and 5,182,782, which are hereby incorporated herein by reference. The support 5 can also be mounted, via solder or epoxy to the external casing base 15. Similarly, supports 13 for supporting the connector 11 can also be soldered or epoxyed to the base 15. Finally, an external cover 17 (preferably plastic or metal) is soldered or epoxyed to base 15 to form an external casing of the optoelectronic package 1. The hermetic seal for the optoelectronic bidirectional transceiver 3 or other optoelectronic component can include initial passive alignment, placement of the cover and then sealing with solder or glass frit. An overmolding or other low pressure encapsulants can be used to encapsulate some of the submodule. Silicon is a preferred hermetic cover, but metal and glass may be used (and even plastic) as discussed previously. The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.

Claims

We claim:

1. An optoelectronic package comprising: an optoelectronic device, including an optical fiber pigtail extending therefrom; a connector including, a ferrule receiving an end of said optical fiber pigtail, and a connector sleeve housing said ferrule; and an external casing housing the optoelectronic device and at least a portion of the connector.

2. The optoelectronic package of claim 1, wherein said optoelectronic device is a hermetically sealed optoelectronic circuit.

3. The optoelectronic package of claim 1, wherein the optoelectronic device is mounted on a support, at an acute angle with respect to said connector sleeve.

4. The optoelectronic package of claim 1, wherein the optoelectronic device is a hermetically sealed silicon submodule.

5. The optoelectronic package of claim 1, wherein said optical fiber pigtail is angled between the optoelectronic device and the ferrule to provide for strain relief in said optical fiber pigtail.

6. The optoelectronic package of claim 1, wherein the ferrule is a spring-loaded ferrule.

7. The optoelectronic package of claim 1, wherein the connector is a split-sleeve connector.

8. The optoelectronic package of claim 1, wherein the external casing is plastic.

9. The optoelectronic package of claim 1, wherein the external casing is metal.

10. The optoelectronic package of claim 3, wherein the external casing includes a base, to which the connector, via supports, and the optoelectronic device support are mounted; and an external cover, connected to the base, housing the optoelectronic device, the ferrule, and at least a portion of the connector.

11. The optoelectronic package of claim 2, wherein optoelectronic components of the hermetically sealed optoelectronic circuit are passively aligned, using silicon waferboard technology.

12. A hermetically sealed bidirectional optical transceiver for use in an optoelectronic package including a ferrule and a connector, housing the ferrule, mounted within the optoelectronic package, the hermetically sealed bidirectional optical transceiver comprising: first optical fiber, for transmitting optical signals therethrough, having an acutely angled endwall; second optical fiber, for transmitting and receiving optical signals therethrough, having an endwall proximate to the acutely angled endwall of the first optical fiber; light source for generating outgoing light; and detector for detecting incoming light, wherein the acutely angled endwall of the first optical fiber reflects at least a portion of the incoming light, passing from the second optical fiber to the detector, and passes at least a portion of the outgoing light to the second optical fiber.

13. The hermetically sealed bidirectional optical transceiver of claim 12, wherein the outgoing light is of a first wavelength and the incoming light is of a second wavelength, different from the first wavelength.

14. The hermetically sealed bidirectional optical transceiver of claim 13, wherein the acutely angled endwall of the first optical fiber includes a dichroic coating.

15. The hermetically sealed bidirectional optical transceiver of claim 12, further comprising: a support, on which at least the light source is mounted, the support being mounted at an acute angle with respect to the connector in the optoelectronic package.

16. The hermetically sealed bidirectional optical transceiver of claim 12, wherein the second optical fiber includes an approximately complementary acutely angled endwall abutting the acutely angled endwall of the first optical fiber.

17. The hermetically sealed bidirectional optical transceiver of claim 16, wherein at least one of the acutely angled endwalls of the first and second optical fibers includes a dichroic coating.

18. The hermetically sealed bidirectional optical transceiver of claim 12, wherein the endwall of the first optical fiber is acutely angled at approximately 45°.

19. The hermetically sealed bidirectional optical transceiver of claim 16, wherein at least one of the acutely angled endwalls of the first and second optical fibers is acutely angled at approximately 45°.

20. The hermetically sealed bidirectional optical transceiver of claim 12, wherein the second optical fiber connects to said ferrule, and is angled between the hermetically sealed bidirectional optical transceiver and the ferrule to provide strain relief in said second optical fiber.

21. The hermetically sealed bidirectional optical transceiver of claim 13, wherein said reflected portion of light of the second wavelength is at least 50 *%'.

22. The hermetically sealed bidirectional optical transceiver of claim 12, wherein said reflected portion of the incoming light is at least 50%.

23. The hermetically sealed bidirectional optical transceiver of claim 13, wherein said passed portion of light of the first wavelength is at least 50%.

24. The hermetically sealed bidirectional optical transceiver of claim 12, wherein said passed portion of the outgoing light is at least 50%.

25. The hermetically sealed bidirectional optical transceiver of claim 12, wherein the proximate acutely angled endwall of the first optical fiber and the endwall of the second optical fiber, proximate to the acutely angled endwall of the first optical fiber, form a beamsplitting junction, the beamsplitting junction being housed by a silicon bridge. - 22 -

26. The hermetically sealed bidirectional optical transceiver of claim 16, wherein the proximate acutely angled endwall of the first optical fiber and the endwall of the second optical fiber, proximate to the acutely angled endwall of the first optical fiber; form a beamsplitting junction, the beamsplitting junction being housed by a silicon bridge, the silicon bridge further supporting the detector and being mounted on the support.

27. The hermetically sealed bidirectional optical transceiver of claim 12, wherein the first optical fiber, second optical fiber, light source and detector are passively aligned.

28. The hermetically sealed bidirectional optical transceiver of claim 12, wherein the outgoing light and the incoming light are of the same wavelength.

29. The optoelectronic package of claim 1, wherein the optoelectronic device is a laser.

30. The optoelectronic package of claim 1, wherein the optoelectronic device is a detector.

31. The optoelectronic package of claim 1, wherein the optoelectronic device is an optical transceiver.

32. The optoelectronic package of claim 11, wherein the optoelectronic device is a laser.

33. The optoelectronic package of claim 11, wherein the optoelectronic device is a detector.

34. The optoelectronic package of claim 11, wherein the optoelectronic device is an optical transceiver.