CN100487508C - Double diffraction grating planar lightwave circuit - Google Patents

Abstract

The invention relates to a planar lightwave circuit including a pair of opposed concave reflective diffraction gratings sharing the same focal line, which separates first and second slab waveguide regions. The ends of input and output waveguides are positioned along the focal line for launching and receiving light directed by one or both of the diffraction gratings. The invention enables light within in a certain wavelength range to be launched from an input waveguide, directed by a single diffraction grating, and output waveguides, all within a single slab waveguide region, while light within another wavelength range will be directed from one diffraction grating to another for output waveguides in a different slab waveguide region.

Description

Double diffraction grating planar lightwave circuit

Technical field

The present invention relates to a kind of double diffraction grating planar lightwave circuit, relate in particular to a kind of (Fiber-to-the-Home that is used in that Fiber to the home, FTTH) (Planar Lightwave Circuit, PLC) the optics single fibre three-way device (triplexer) of the planar lightwave circuit in the Optical Access Network.

Background technology

Single fibre three-way device or sound-data-video (VDV) processor serves as from FTTP light net and enters optics gateway the user family.Single fibre three-way device is a connection device very small and exquisite and that cost is very low, and it can receive two IA High Speed Channel, and (for example: 1490nm is used for the transmission of phone and the Internet signal; 1550nm is used for video signal transmission) signal, and simultaneously go up transmission signals at the 3rd channel (for example 1310nm is used for signal output).Simple in order to lay, all these signals are multiplexed on the simple optical fiber.

Typical single fibre three-way device demand has proposed sizable challenge to conventional P LC designing technique.In the optical texture laser instrument must be arranged, wavelength is 1310nm usually, is coupled to a single-mode fiber, is used for transmitting the optical signalling from user family.At the other direction of same optical fiber, nominally from the wavelength of open air for the light of 1490nm and 1550nm be acquired, by demultiplexing and exported to fluorescence detector.Because exercisable passband has caused difficult increasing on these wavelength.At the 1310nm channel, expected bandwidth be 50nm to 100nm, this just provides a big scope, in this scope, in fact laser instrument can not have the thermal technology and does, and wherein only needs the bandwidth of 10nm to 20nm for detector channel.Or rather, light emitting diode is operated in single lateral mode, and I/O optical fiber commonly used is single-mode fiber, therefore has a few necessarily consistent with single mode optics along the track of laser channel in institute.In other words, the track of laser channel must be reversible.In the prior art, particularly adopt these designing techniques of single diffraction structure in PLC, the channel that does not have practical way utilization to have different basically passbands is selected the wavelength coverage (～1250nm is to 1600nm) of broad.

Prior art equipment, for instance, authorized the patent No. 6 of Althaus in Dec 10 in 2002,493,121 U.S. Patent Publication such equipment, as shown in Figure 1, adopt many independently, exquisite Thin Film Filter (the thin film filters that makes, TFF) 2a and 2b, they are placed on the ad-hoc location along collimated light path, have realized the function of VDV processor (single fibre three-way device 1).TFF 2a and TFF 2b and discrete lasers 3, photoelectric detector 4a and photoelectric detector 4b coupling, and (Transistor-Outline TO) in the encapsulation 6, is assembled into an assembly then to be encapsulated in independently column type.The input signal that has two input channels (1490nm and 1550nm) enters single fibre three-way device 1 by optical fiber 7.First channel is by a TFF 2a demultiplexing, and is directed to the first photoelectric detector 4a; Second channel is by the 2nd TFF 2b demultiplexing, and is directed to the second photoelectric detector 4b.In laser instrument 3, generate delivery channel (1310nm) and pass through a TFF 2a and the 2nd TFF 2b output optical fibre 7.Unfortunately, the assembling of these devices is very accurate, and it is very little to require all elements to be adjusted to build-up tolerance.

In order to attempt to simplify shell mechanism, therefore 4 disclosed, as to authorize people such as Althaus U.S. Patent number 6,731,882 May in 2004 and June in 2004 people such as the disclosed Melchoir of authorizing on the 29th 6,757,460 patent in introduced assembly technology.For further improvement, as shown in Figure 2, be included in semiconductor microactuator device (microbench) and go up all components and parts of configuration, assurance can repeat and accurately adjust.Unfortunately, all these solutions still involve the adjustment problem of a plurality of TFF that have the TO encapsulation.On February 17th, 2004 is disclosed authorizes introduced prior art in people's such as Baumann the United States Patent (USP) 6,694,102 one not with the solution of TFF, has wherein introduced a kind of bidirectional multiplexer of utilizing a plurality of Mach-Zehnder interferometers.

Defective by utilizing the double diffraction mounting for grating to provide the planar lightwave circuit three-way device to overcome prior art is provided, and this double diffraction mounting for grating can realize having the application of broad wavelength coverage of the channel of different passbands.

Summary of the invention

Therefore, a kind of planar lightwave circuit Wavelength-division multiplexer/demultiplexer involved in the present invention, it comprises:

Planar waveguide, it limits first and second flat areas that connected by the gap;

The first and second face-to-face recessed reflecting diffraction gratings, it is positioned at each end of planar waveguide;

First waveguide, it extends to first flat area;

Second waveguide, it extends to first flat area;

The 3rd waveguide, it extends to second flat area;

Wherein the end of first and second reflection gratings and first, second, third waveguide is placed, wavelength light in the wavelength coverage of winning will be transmitted between first and second waveguides by first grating, and therefore the light of the wavelength in second wavelength coverage will transmit between the described first and the 3rd waveguide by described first and second gratings, and the wavelength of described second wavelength coverage is higher than or is lower than the wavelength of described first wavelength coverage.

Description of drawings

Below in conjunction with the more detailed the present invention of introduction of the accompanying drawing of representing preferred embodiment, wherein;

The conventional films optical filter that is based on single fibre three-way device shown in Figure 1;

The conventional films optical filter that is based on the single fibre three-way device that adopts semiconductor chip shown in Figure 2;

Shown in Figure 3 is traditional reflecting diffraction grating;

Figure 4 shows that the double diffraction mounting for grating that band that the present invention introduces is lost lustre diffusing;

Figure 5 shows that the multiplexer/demultiplexer of the employing double diffraction mounting for grating that Fig. 4 introduces;

Figure 6 shows that the single fibre three-way device of the employing double diffraction mounting for grating that Fig. 4 introduces;

Figure 7 shows that the response curve of the fine three-way device of throwaway of losing lustre that Fig. 4 introduces;

Figure 8 shows that the present invention introduces with hyperchromic diffusing double diffraction mounting for grating;

Figure 9 shows that the single fibre three-way device of the employing enhancing double diffraction mounting for grating that Fig. 8 introduces; With

Figure 10 shows that the response curve of the fine three-way device of hyperchromic throwaway that Fig. 8 introduces.

Detailed description of preferred embodiment

The plane light wave reflecting diffraction grating comprises one group of facet of arranging by particular order.The characteristic of single diffraction grating is introduced with reference to Fig. 3.Light beam 11 comprises a plurality of wavelength channel ₁, λ ₂, λ ₃..., with specific incident angle θ _InInject diffraction grating 12, the segmentation gradient is that Λ and diffraction exponent number are m.According to wavelength and diffraction exponent number, this light beam is with angle θ subsequently _OutBe spread out, according to grating equation:

mλ＝Λ(sinθ _in+sinθ _out) (1)

From grating equation (1), by lambda1-wavelength λ _NDetermine the formation of diffraction exponent number.When considering that spectrum constitutes, must known diffraction angle _NoutBe how with the incident angle θ of incident light _InChange.Therefore, equation (1) is asked about θ _NoutDifferential, suppose incident angle θ _1nConstant, derive following formula:

${\∂\mathrm{\θ}}_{\mathrm{Nout}}/\∂\mathrm{\λ}=m/{\mathrm{\Λ}\cos \mathrm{\θ}}_{\mathrm{Nout}}---\left(2\right)$

Amount d θ _Nout/ d λ is the corresponding diffraction angle of little variation with wavelength X _NoutVariation, this is known as the angular dispersion (angular dispersion) of diffraction grating.Angular dispersion is along with the increasing of exponent number m, reduction and the diffraction angle of segmentation gradient Λ _NoutStrengthen and increase.The linear dispersion of diffraction grating (linear dispersion) is the product of this (angular dispersion) and system's effective focal length.

Because different wave length λ _NLight with different angle θ _NoutDiffraction takes place, and each exponent number m is introduced in the spectrum.The exponent number that is generated by a given diffraction grating is limited by segmentation gradient Λ, because θ _NoutCan not be above 90 °.Top step number is by Λ/λ _NDetermine that so coarse grating (big Λ) can generate a lot of grades of spectrum, and fine grating can only generate single order or second order spectrum.

With regard to single fibre three-way device, be 100nm for the corresponding passband of laser instrument, for the corresponding passband of detector channel be～20nm.Realize that with single diffraction structure such device is unpractical, because each channel is with shared public physical dispersion (physical dispersion).Suppose the beam split flat area through selected, the guiding duct width of minimum operational can be handled the passband of 20nm in grating output like this.For the passband channel of 100nm, if reversible track is necessary, duct width wants enough wide so that can support various mode so, need make simultaneously to have the extremely sensitive device of manufacturing tolerance.

According to above-mentioned equation (1), output angle can be separated, and is given by following formula:

${\sin \mathrm{\θ}}_{\mathrm{out}}=\frac{\mathrm{m\λ}}{\mathrm{\Λ}}-\sin {\mathrm{\θ}}_m---\left(3\right)$

That equation (3) illustrates is output angle θ _OutDirectly with wavelength X _NVariation relation, suppose that input angle is a fixed value, this situation occurs in: from single multiplexed beam of the single waveguide emission that is positioned at first diffraction grating.

Following equation is obtained by separating the input angle derivation by equation (1):

${\sin \mathrm{\θ}}_m=\frac{\mathrm{m\λ}}{\mathrm{\Λ}}-\sin {\mathrm{\θ}}_{\mathrm{out}}---\left(4\right)$

Therefore, if second grating is placed on output place of first grating and suitably selects exponent number (m ₂), the gradient (Λ ₂) and the I/O angle, as long as the variation of the first grating output angle (equation 3) is identical with the variation of the second grating input angle (equation 4), just can stablize the output angle of second grating relevant with wavelength.

Described in Fig. 4 is the basic operation situation of double grating structure of loosing that loses lustre.The input light of setted wavelength scope is gone out from the edge-emission of planar lightwave circuit (PLC) 20a via input waveguide 21.Input light arrives input 22 places and enters the first planar waveguide zone 23, and this zone comprises the first recessed reflecting diffraction grating 24.First grating 24 focuses the light on a certain position of focal line 26, and this position changes with wavelength change.Focal line 26 (using Rowland circle (Rowland circle) expression here, although other embodiment also is fine) also is the focal line of the second recessed reflecting diffraction grating 27.The light that comes from first grating 24, it focuses on along focal line 26, passes through slit 28 and enters second planar waveguide 29, and illuminate second grating 27.The light that exceeds the setted wavelength scope can not pass through slit 28, and can assemble by the additional waveguide that extends to first waveguide region 23 from chip 20a edge, and is as mentioned below.Second grating 27 focuses on the exit point 31 light again, and light is caught and exported by output waveguide 32 herein.Select the position of exit point 31 and the parameter (exponent number m and gradient Λ) of second grating 27, so that the variation that fine compensation causes owing to the change of wavelength along the focal line 26 of first grating 24.So, come from light imaging on exit point 31 of input waveguide 21, and be output to the output terminal of device and and Wavelength-independent.This device expection can be flated pass defeated to wavelength.In actual applications, because a variety of causes, this transmission will not be complete and Wavelength-independent.The focal line 26 of first grating 24 can only approach the focal line of second grating 27, except the special circumstances of flat field (flat-field) design.Even now, when the input position of second grating 27 when focal line 26 changes, the illumination of second grating 27 also will change.But the planarization of the essence of wavelength dependent transmission still can realize.

With reference to Fig. 5, the diffusing double grating device of losing lustre according to the present invention can be used as Wavelength-division multiplexer/demultiplexer (Wavelength Division Multiplexer/Demultiplexer), or rather, can be used as the multiplexer of partial wave or logical ripple, in this device, the light with a plurality of wavelength channels is launched via the edge of first port (just input waveguide 21) from the PLC 20b that is positioned at first concave reflection grating 24.First grating 24 is isolated one or more wavelength channels in first wavelength coverage, and goes up the light of assembling these wavelength in independent output waveguide (for example 33 and 34) respectively.Remaining light, promptly in having second wavelength coverage of higher or lower wavelength, passing through slit 28 is mapped on second reflection grating 27, its guiding also focuses on this light (just in second wavelength coverage) in the waveguide 32, its passband specific output waveguide 33 and 34 channels output pass band 2,3,4 or 5 times.The light of pass through slit 28 in wavelength coverage, injecting the first planar waveguide zone 23 from another input waveguide 41 will be coupled to different output waveguides, and for example waveguide 42.

For adopting same structure by the multiplexed optical wavelength channel of waveguide 32 emissions with by waveguide 33 and 34 light wavelength channel of launching.In second wavelength coverage, come from the wavelength channel of waveguide 32, pass second grating 27, pass through slit 28, leave first grating 24, enter waveguide 21.In first wavelength coverage, come from the wavelength channel of waveguide 33 and 34, directly leave first grating 24 and enter waveguide 21.

With reference to Fig. 6, make a single fibre three-way device, it combines the characteristics of Fig. 4 and Fig. 5.Carry two (or a plurality of) information channels (for example, 1490nm and 1550nm) input light and be launched away via waveguide 21, this waveguide 21 becomes by the I/O waveguide of optical coupled to the FTTH optical-fiber network.The first concave reflection grating device, 24 usefulness suitable manner, will import light with the passband of 20-30nm and be dispersed into selected wavelength, and dispersed beamlet be gathered respectively on the end of first output waveguide 33 and second output waveguide 34, it is on focal line 26.If desired, can increase other output waveguide, its contiguous first waveguide 33 and second waveguide 34 are so that catch other required wavelength.Photodetector array 36 (for example photodiode) be placed on output waveguide 33 with 34 relative terminal, be used for light signal is converted to electric signal.

Output signal light wavelength channel (channel) so that relative direction is propagated for example at the 1310nm channel, is derived from lasing light emitter 37, and this lasing light emitter 37 is by the edge of optical coupled to PLC 20c.For laser channel, to such an extent as to the too high laser channel of required actual dispersion is captured in the waveguide.On the contrary, laser is via waveguide 32 emissions that extend to focal line 26,27 places enter the second planar waveguide zone 29 at second concave reflection grating, second concave reflection grating 27 focuses on light along focal line 26, and direct light is passed through slit 28 and is arrived first concave reflection grating, 24, the first concave reflection gratings 24 and be shaped so that the light of dispersion can not enter I/O waveguide 21.Second grating 27 is relative with the actual wavelength chromatic dispersion of first grating 24 (it is diffusing to lose lustre), therefore for the optical wavelength of two gratings of experience, can reduce, eliminate, reverse its clean actual dispersion.Because reflection grating 24 and reflection grating 27 are arranged, as mentioned above,,, be reversible along the track of laser channel for the arbitrary wavelength in the wavelength coverage to stablize the output angle of different wave length, arbitrary wavelength will be through slit 28.

As shown in Figure 7, in bulk the putting of losing lustre, based on the use of two kinds of gratings, the optical maser wavelength of right～1310nm surpassing on the 100nm bandwidth, has obtained very smooth transmission passband.The detector channel of 1490nm and 1550nm only experiences a grating separately, and they only are dispersed into very narrow bandwidth.

In the VDV processor, between the receiver channels of the lasing light emitter of 1310nm and 1490nm and 1550nm, need sometimes isolating near 50dB.In the device based on grating, the main light source of bias light results from because the scattering that the defective on the planar side causes.Thereby plane self is arranged with the interference dispersion of generation phase coherence and by wavelength ad hoc fashion focused light.Turning between the sidewall of reflecting surface and non-reflecting surface (corner rounding) also is periodic, thereby guarantees Space Consistency, but owing to unsuitable phase place, causes occurring the periodicity emphasis picture of low-light level.The degree of roughness on plane will spatially be incoherent, cause occurring low-level bias light at random.Therefore, if strong laser signal incides on the grating, and receiver channels also obtained this signal from this grating, and receiver channels will have the strong bias light that produces owing to laser instrument so, and its typical rank that is lower than laser instrument intensity is 30dB.The requirement of practical VDV processor is more approached at the interval of～50dB.

If second grating is placed on output place of first grating, and correctly select exponent number (m ₂), the gradient (Λ ₂) and angle, so just can be by utilizing because first grating scattering causes the second grating input angle to change that these two variations change the second grating output angle relevant with wavelength with wavelength variations.

Fig. 8 has shown the principle of work that is designed to improve the isolated hyperchromic diffusing double diffraction optical grating construction of lasing light emitter and receiver.Input signal comprises a plurality of light wavelength channel, and it is transmitted into the input port 52 in the first planar waveguide zone 53 along input waveguide 51 from the edge of PLC 50a.Signal is directed to first concave diffraction grating, 54, the first concave diffraction gratings 54 input signal is scattering into the wavelength channel of formation, and they are focused on along focal line 56, and its focal position changes with the change of wavelength.Focal line 56 (using Rowland circle (Rowland circle) expression here, although other embodiment also is fine) also is the focal line of the second recessed reflecting diffraction grating 57.Light in designated wavelength range, 58 propagate through the gap, pass through second waveguide region 59 and arrive second grating 57.Second grating 57 is the further scattering of these light, and different wavelength channels is focused to exit point 61a again along focal line 56, and 61b etc. locate, and herein according to wavelength, they are output waveguide 62a, catch for one among the 62b etc.Select exit point 61a, the parameter of the position of 61b etc. and second grating 57 (exponent number m and gradient Λ), just can strengthen change owing to wavelength and make the variation that takes place along the focal position of second grating, 57 focal lines 56, at exit point 61a, 61b etc. locate to produce level and smooth bigger physical dispersion.Therefore, at exit point 61a, 61b etc. locate imaging from the light of input waveguide 51, and with light extraction to output terminal with device bigger than independent employing first grating 54 or the 57 resulting scattering processes of second grating.When comparing with the device that only uses a grating in the grating, this device is supposed to have narrower transmission bandwidth to wavelength.

With reference to Fig. 9, hyperchromic diffusing double diffraction grating among Fig. 8 has been made less modification (for example Fu Jia input waveguide 63) so that the function of single fibre three-way device to be provided.The laser that comes from the 1310nm of laser instrument 64 penetrates from the edge of chip 50b and enters input waveguide 63, and the end of waveguide 63 is positioned on the focal line 56, and propagates into the first concave reflection grating device 54 along the first planar waveguide zone 53.Grating 54 is in mode easily, promptly utilizes the 100nm passband of laser channel will import recovery and uses first waveguide, 51, the first waveguides 51 and serve as the I/O waveguide, and its end also drops on the focal line 56.Light leaves the first I/O waveguide 51 along the edge of chip, is transferred to the FTTH network.The input light of 1490nm and 1550nm enters the first I/O waveguide 51, along the reverse direction transmission of 1310nm laser.The light of 1490nm and 1550nm channel passes to the first concave reflection grating device 54 by first planar waveguide 53, is being scatter near focal line 56 places.The required physical dispersion of light is designed to be too low so that be not enough to the detector channel and first mounting for grating 54 are made a distinction.Light is transferred to the second planar waveguide zone 59 on second concave reflection grating 57 by gap 58, such structural design is used to strengthen scattering process, therefore the light of 1490nm and 1550nm channel is fully disperseed to receive to be output waveguide 62a and 62b respectively, and its end also is to drop on the focal line 56.Bandwidth 20nm enters photoelectric detector 66a and 66b to two channels of 30nm passband from the chip edge ejaculation.For specific wavelength bandwidth (being the bandwidth of 1260-1360nm), be reversible along the track of laser channel.Because the laser beam of 1310nm is intercepted and captured on getting to first grating 54 time immediately, this light is mapped to and obtains only 1310nm ray on second grating 57 after first grating 54 is left in scattering.The light intensity of expectation is degree～30dB, and is lower than laser intensity.The ray of 1310nm got on second grating 57～and the light of 30dB further weakens, and as what see at waveguide 62a or 62b place, is the rays that are used for catching 1490nm and 1550nm because settle these waveguides.Therefore, just might obtain laser beam～60dB independent light from detector channel.Therefore, additional diffusing structure has very high level of isolation.

With the double grating similar of loosing that loses lustre, light in first wavelength coverage of launching from I/O waveguide 51 or input waveguide 63 is propagated along focal line 56, but rest on the first planar waveguide zone 54, and the light transmission gap 58 in second wavelength coverage arrives second grating 57.The dissipating bind structure is opposite with losing lustre, rest on the first tabular waveguide region 53 by I/O waveguide 51 light emission, that comprise 1310nm channel wavelength scope, and the light crossing gap 58 that comprises detector channel 1490nm and 1550nm wavelength coverage is mapped on second grating 57.

As shown in figure 10, the transmission passband of detector channel is very narrow, and laser channel is quite wide.The detector channel of 1490nm and 1552nm is respectively through two gratings, and they are dispersed in the very narrow bandwidth, and just 20nm is to the bandwidth of 30nm.The 1310nm ray is is only intercepted and captured by a following grating, just has the above bandwidth of 100nm, and this has just improved the level of isolation between laser beam and the detector channel, can reach the level of isolation on the 45dB in these cases.For master grating, level of isolation is significantly improved by typical 30dB, and has only by using the hyperchromic dissipating bind structure of double grating just might realize.

Claims (19)

1. planar lightwave circuit Wavelength-division multiplexer/demultiplexer device, it comprises:

Planar waveguide, it limits first and second flat areas that are connected by the gap;

The first and second face-to-face recessed reflecting diffraction gratings, it is positioned at each end of described planar waveguide;

First waveguide, it extends to described first flat area;

Second waveguide, it extends to described first flat area;

The 3rd waveguide, it extends to described second flat area;

The end of wherein said first and second gratings and described first, second, third waveguide is placed, the light of the wavelength in the wavelength coverage of winning will be transmitted between described first and second waveguides by described first grating, and therefore the light of the wavelength in second wavelength coverage will transmit between the described first and the 3rd waveguide by described first and second gratings, and the wavelength of described second wavelength coverage is higher than or is lower than the wavelength of described first wavelength coverage;

Wherein, described first and second gratings have same focal line; And

Wherein, the end of described first and second waveguides is positioned on the focal line on one side of described gap, and the end of described the 3rd waveguide is positioned on the focal line on the opposite side of described gap.

2. planar lightwave circuit Wavelength-division multiplexer/demultiplexer device according to claim 1, wherein, described focal line is limited by Rowland circle.

3. planar lightwave circuit Wavelength-division multiplexer/demultiplexer device according to claim 1, wherein, the physical dispersion of described second grating is opposite with the physical dispersion of described first grating, and therefore in fact all light wavelength channel in described second wavelength coverage will be propagated between the described first and the 3rd waveguide.

4. planar lightwave circuit Wavelength-division multiplexer/demultiplexer device according to claim 3, also comprise from extended the 4th waveguide of described first flat area, wherein said first waveguide can be launched first light signal that comprises first and second light wavelength channel, and described first and second light wavelength channel are positioned at described first wavelength coverage at the described first grating place; And wherein said first grating can disperse described first and second light wavelength channel, and described first and second light wavelength channel can be focused on respectively in the described second and the 4th waveguide.

5. planar lightwave circuit Wavelength-division multiplexer/demultiplexer device according to claim 4, wherein, described the 3rd waveguide can be launched second light signal that comprises the 3rd light wavelength channel in described second wavelength coverage, and described second light signal is focused in described first waveguide by described first and second gratings.

6. planar lightwave circuit Wavelength-division multiplexer/demultiplexer device according to claim 5, wherein, the light wavelength channel passband of leaving from described both reflections of first and second gratings is than 2 to 5 times of the light wavelength channel pass bands that only leaves from described first optical grating reflection.

7. planar lightwave circuit Wavelength-division multiplexer/demultiplexer device according to claim 5, wherein, the passband of described first and second light wavelength channel is respectively 20nm to 30nm, and the passband of wherein said the 3rd light wavelength channel is 100nm.

8. planar lightwave circuit Wavelength-division multiplexer/demultiplexer device according to claim 7, wherein, the passband of described first and second light wavelength channel is limited by the centre wavelength of 1490nm and 1550nm respectively, and the passband of wherein said the 3rd light wavelength channel is limited by the centre wavelength of 1310nm.

9. planar lightwave circuit Wavelength-division multiplexer/demultiplexer device according to claim 5 also comprises:

Laser instrument, it to described the 3rd waveguide, is used to produce described second light signal by optical coupled; And

First and second photoelectric detectors, it, is used for converting described first and second light wavelength channel to electric signal to the described second and the 4th waveguide by optical coupled.

10. planar lightwave circuit Wavelength-division multiplexer/demultiplexer device according to claim 1, wherein, the physical dispersion of described second grating has strengthened the physical dispersion that is caused by described first grating, therefore in described second wavelength coverage only a light wavelength channel will between the described first and the 3rd waveguide, transmit.

11. planar lightwave circuit Wavelength-division multiplexer/demultiplexer device according to claim 10, also comprise from extended the 4th waveguide of described second flat area, wherein said first waveguide can be launched first light signal that comprises first and second light wavelength channel, described first and second light wavelength channel are being positioned at described second wavelength coverage at the described first grating place, and described first grating and described second grating scatter described first and second light wavelength channel jointly and described first and second light wavelength channel are focused on respectively in described third and fourth waveguide.

12. planar lightwave circuit Wavelength-division multiplexer/demultiplexer device according to claim 11, wherein, described second waveguide can be launched second light signal that comprises the 3rd light wavelength channel in described first wavelength coverage, and described second light signal is focused in described first waveguide by described first grating.

13. planar lightwave circuit Wavelength-division multiplexer/demultiplexer device according to claim 12, wherein, the light wavelength channel passband of only leaving from described first optical grating reflection is than 2 to 5 times of the light wavelength channel pass bands that leaves from described both reflections of first and second gratings.

14. planar lightwave circuit Wavelength-division multiplexer/demultiplexer device according to claim 12, wherein, the passband of described first and second light wavelength channel is respectively 20nm to 30nm, and wherein, the passband of described the 3rd light wavelength channel is 100nm.

15. planar lightwave circuit Wavelength-division multiplexer/demultiplexer device according to claim 14, wherein, the passband of described first and second light wavelength channel is limited by the centre wavelength of 1490nm and 1550nm respectively; Wherein, the passband of described the 3rd light wavelength channel is limited by the centre wavelength of 1310nm.

16. planar lightwave circuit Wavelength-division multiplexer/demultiplexer device according to claim 12 also comprises:

Laser instrument, it to described second waveguide, is used to produce described second light signal by optical coupled; And

First and second photoelectric detectors, it, is used for converting described first and second light wavelength channel to electric signal to described third and fourth waveguide by optical coupled.

17. planar lightwave circuit Wavelength-division multiplexer/demultiplexer device according to claim 11, wherein, described first light signal also comprises the 3rd light wavelength channel in described first wavelength coverage, and described first light signal is focused in described second waveguide by first grating.

18. planar lightwave circuit Wavelength-division multiplexer/demultiplexer device according to claim 1, light wavelength channel another light wavelength channel in second wavelength coverage that launch from described the 3rd waveguide, described that wherein, will launch from described second waveguide, in described first wavelength coverage is multiplexed in described first waveguide.

19. planar lightwave circuit Wavelength-division multiplexer/demultiplexer device according to claim 1, wherein, light wavelength channel in described first wavelength coverage that will launch from first waveguide and another light wavelength channel demultiplexing that launch from first waveguide, in described second wavelength coverage, and they are focused on respectively in the described second and the 3rd waveguide.

Images