A frequency-stabilized semiconductor laser oscillator in which a control signal derived from a modulation signal is applied to a second optical waveguide adjacent the first optical waveguide in order to make the overall optical path between both waveguides constant despite variations in the refractive...http://www.google.es/patents/US4669086?utm_source=gb-gplus-sharePatente US4669086 - Frequency-stabilized semiconductor laser oscillator
