JP2000077771A5 - - Google Patents

Description

(11) Regarding the above (9), the distributed Bragg reflector is used as the reflecting mirror 4 having wavelength selectivity, comprising the distributed Bragg reflector from the semiconductor optical amplifier 2 and the electroabsorption modulator It is characterized by being monolithically integrated with a variable light attenuator.

(18) Further, according to the present invention, in the gain clamp type semiconductor optical amplifier 1 composed of the semiconductor optical amplifier 2 and the laser resonator including the semiconductor optical amplifier 2 inside, the semiconductor optical amplifier 2 is sanc-type optical. A laser resonator is constructed by arranging a reflector on an optical waveguide connected to one input / output port of the sanac type optical interferometer while being provided on the arm of the interferometer , and a variable optical amplifier 3 is provided in the optical waveguide. Is arranged, and the optical waveguide connected to the other input / output port is used as an input / output optical waveguide for the signal light 7.

In this way, when a sanac type optical interferometer is used, only one semiconductor optical amplifier 2 is required, so that a gain clamp type semiconductor optical amplifier 1 having a symmetrical structure using a pair of semiconductor optical amplifiers 2 can be used. In comparison, the requirement for symmetric operability required for the semiconductor optical amplifier 2 is not required, so that the possibility that the laser oscillation light and the signal light 7 are mixed is further reduced, and stable optical amplification operation becomes possible.
Further, by arranging the variable optical attenuator 3 in the optical waveguide constituting the laser resonator, the resonator loss can be continuously and arbitrarily controlled, whereby the gain clamp type semiconductor optical amplification device 1 can be controlled. The characteristics of can be optimized according to the application.

Claims (23)

  In a gain clamp type semiconductor optical amplifying device comprising a semiconductor optical amplifier and a laser resonator including the semiconductor optical amplifier, laser oscillation light while maintaining an effective transmission loss amount for signal light at a constant value. A semiconductor optical amplifying device comprising a variable optical attenuating mechanism capable of controlling the amount of resonator loss with respect to.   2. The semiconductor according to claim 1, wherein at least one of the laser resonators is constituted by a reflecting mirror having wavelength selectivity, and a variable optical attenuator is provided in the laser resonator as the variable optical attenuation mechanism. Optical amplification device.   3. The semiconductor optical amplifying device according to claim 2, wherein a portion through which the signal light does not pass is provided in the laser resonator, and the variable optical attenuator is disposed at a portion through which the signal light does not pass.   The laser resonator has an external resonator structure composed of a wavelength-selective reflector and a non-wavelength-selective reflector, and a beam splitter is inserted between the wavelength-selective reflector and the semiconductor optical amplifier. In addition, signal light is incident from a direction perpendicular to the laser resonator through the beam splitter, and the signal light is not passed between the wavelength selective reflector and the beam splitter. The semiconductor optical amplifier according to claim 3.   The laser resonator has an external resonator structure composed of a wavelength-selective reflector and a non-wavelength-selective reflector, and a beam splitter is inserted between the wavelength-selective reflector and the semiconductor optical amplifier. In addition, the signal light is emitted from a direction perpendicular to the laser resonator through the beam splitter, and the signal light does not pass between the wavelength selective reflector and the beam splitter. The semiconductor optical amplifier according to claim 3.   The laser resonator has an external resonator structure composed of a pair of wavelength-selective reflectors, and a beam splitter is inserted between the semiconductor optical amplifier and both the wavelength-selective reflectors, and Signal light enters and exits from a direction perpendicular to the laser resonator through a beam splitter, and the signal light does not pass through two regions between the pair of wavelength-selective reflectors and the beam splitter; 4. The semiconductor optical amplifier according to claim 3, wherein   A variable optical attenuator in which the amount of optical attenuation can be changed with respect to the laser oscillation wavelength as the variable attenuator without providing a portion through which the signal light does not pass in the laser resonator, but the signal light is not effectively attenuated. The semiconductor optical amplifier according to claim 2, wherein:   Electroabsorption type light having an absorption edge wavelength shorter than the laser oscillation wavelength as the variable optical attenuator while setting the laser oscillation wavelength shorter than the wavelength of the signal light by the wavelength selective reflector. 8. The semiconductor optical amplifier according to claim 7, wherein a modulator is used.   9. The semiconductor optical amplifier according to claim 8, wherein the semiconductor optical amplifier and the variable optical attenuator comprising the electroabsorption optical modulator are monolithically integrated.   The semiconductor optical amplifier according to claim 7, wherein a fiber grating is used as the wavelength-selective reflecting mirror. A distributed Bragg reflector is used as the wavelength selective reflector, and the distributed Bragg reflector is monolithically integrated with a variable optical attenuator composed of the semiconductor optical amplifier and the electroabsorption optical modulator. The semiconductor optical amplifier according to claim 9.   The semiconductor optical amplifier is provided in two arms of a Mach-Zehnder interferometer including two 2 × 2 type optical couplers, and the laser resonator is connected to one of the input ports of the optical coupler on the input side and the input port The variable optical attenuator as the variable optical attenuation mechanism includes the optical coupler and the optical coupler in the laser resonator, and a reflecting mirror disposed at the output port of the optical coupler at the output side in the cross position. 2. The semiconductor optical amplifier according to claim 1, wherein the semiconductor optical amplifier is provided between the reflecting mirror and the reflecting mirror.   13. The semiconductor optical amplifier according to claim 12, wherein a directional coupler is used as the 2 × 2 type optical multiplexer / demultiplexer.   13. The semiconductor optical amplifier according to claim 12, wherein a multimode interferometer is used as the 2 × 2 type optical multiplexer / demultiplexer.   15. The semiconductor optical amplifying device according to claim 12, wherein at least one of the reflecting mirrors is constituted by a reflecting mirror having wavelength selectivity.   16. The semiconductor optical amplifier according to claim 12, wherein an electroabsorption optical modulator is used as the variable optical attenuator.   17. The semiconductor optical amplifier, the two 2 × 2 type optical multiplexer / demultiplexers, the variable optical attenuator, and the reflecting mirror are monolithically integrated. Semiconductor optical amplifier. In a gain clamp type semiconductor optical amplifier comprising a semiconductor optical amplifier and a laser resonator including the semiconductor optical amplifier therein, the semiconductor optical amplifier is provided on an arm of a Sagnac optical interferometer, and the Sagnac optical light is provided. An optical waveguide connected to one input / output port of the interferometer to form a laser resonator by arranging a reflecting mirror and a variable optical attenuator arranged in the optical waveguide and connected to the other input / output port A semiconductor optical amplifying device characterized in that an optical waveguide for input / output for signal light is used.   19. The semiconductor optical amplifier according to claim 18, wherein a reflecting mirror having wavelength selectivity is used as the reflecting mirror.   20. The semiconductor optical amplifying device according to claim 18, wherein the optical waveguide portion and the optical coupler portion other than the semiconductor optical amplifier in the Sagnac type optical interferometer are constituted by optical fibers.   20. The semiconductor optical amplifier according to claim 18, wherein the optical waveguide portion and the optical coupler portion other than the semiconductor optical amplifier in the Sagnac type optical interferometer are constituted by a planar dielectric optical circuit.   20. The semiconductor optical amplifier according to claim 18, wherein the optical waveguide, the optical coupler portion, the arm, and the semiconductor optical amplifier constituting the Sagnac optical interferometer are monolithically integrated with a semiconductor.   23. The semiconductor optical amplification device according to claim 22, wherein the optical waveguide, the optical coupler portion, and the arm constituting the Sagnac type optical interferometer are also used as a semiconductor optical amplification region.