摘要:
An optical amplifier on a silicon platform includes a first doped device layer and a second doped device layer. A gain medium is positioned between the first and second doped device layers. The gain medium comprises extrinsic gain materials so as to substantially confine in the gain medium a light signal and allow the optical amplifier to be electrically or optically pumped.
摘要:
An optical amplifier on a silicon platform includes a first doped device layer and a second doped device layer. A gain medium is positioned between the first and second doped device layers. The gain medium comprises extrinsic gain materials so as to substantially confine in the gain medium a light signal and allow the optical amplifier to be electrically or optically pumped.
摘要:
An optical device includes an optically emitting material producing spontaneous emission and an optical waveguide coupled to the optically emitting material. The spontaneous emission from the optically emitting material is emitted into at least one optical mode of the optical waveguide. The optical waveguide coupled to the optically emitting material does not provide optical gain, and the presence of the optical waveguide causes the spontaneous emission rate to be substantially more rapid than in the absence of the optical waveguide. The optical waveguide causes the more rapid spontaneous emission rate over a broad range of frequencies.
摘要:
A fiber laser or fiber amplifier uses resonant pumping of the gain medium by providing a pump resonator that establishes a resonator cavity at the pump wavelength which includes the pumped gain medium. The pump resonator may be of a distributed feedback (DFB) or a distributed Bragg reflector (DBR) type construction, and may be combined with signal reflection apparatus of either DFB or DBR type construction that provides oscillation of the desired laser output wavelength. If used without a signal reflection apparatus, the invention may be operated as a resonant pumped fiber amplifier. Multiple resonators may also be pumped by a single pump source by locating each in a different branch of a multiple branch directional coupler. If the resonators are constructed to couple their outputs away from the coupler, a plurality of different laser outputs each having a different wavelength and equal output powers is provided. If the resonators couple their outputs toward the coupler, a plurality of discrete wavelengths each at the same power may be coupled onto a single waveguide. The pumping of the resonators may be from a single source the output of which is coupled into the single waveguide toward the directional coupler using a wavelength selective optical coupler that prevents optical energy outside the wavelength range of the pumping energy from reaching the pumping source.
摘要:
A method and device for obtaining a desired phase of optical characteristic of a Fabry-Perot (FP) etalon using multiple optical detectors which, while passively aligned at various positions relative to an incident light beam, detect different phases of light signal emerging from the FP etalon. An FP etalon and optical detector array constructed in accordance with the present invention may be used as a frequency discriminator in an optical system where the FP etalon optical characteristic is required to have a particular phase.
摘要:
The disclosed article comprises a semiconductor laser (typically a multi-segment DBR laser) and feedback means for controlling the laser wavelength. The wavelength reference element in the feedback means advantageously is an optical fiber comprising an in-line refractive index grating. Such gratings frequently have a transmission spectrum that exhibits subsidiary lobes, in addition to the desired main lobe, potentially compromising the "cold-start" ability of prior art systems. This and other drawbacks of prior art systems exemplarily are overcome by apparatus that comprises a feedback loop that comprises means for causing a current I.sub.B to flow to the "Bragg" section of a multi-segment DBR laser such that wavelength of the laser output is a function of I.sub.B, and that further comprises means for changing the temperature of the laser in response to a change in the wavelength of the laser. Use of a wavelength reference element that has a relatively wide primary minimum facilitates cold starting. Exemplarily, the disclosed article is a wavelength division multiplexed (WDM) optical fiber communication system.
摘要:
Various optical functions are generated in accordance with the present invention of a novel broadly tunable monolithic wavelength selective coupler which can be integrated with a gain medium to form a broadly tunable laser. The tunable wavelength selective coupler supports a pair of asynchronous waveguides, an upper waveguide and a lower waveguide, in combination with a phase match course grating for coupling optical energy between said waveguides. One end of the lower waveguide terminates at an output facet. The corresponding end of the upper waveguide terminates in an optical signal absorbing medium. The other end of the lower waveguide is terminated to prevent optical energy from entering the waveguide; and, the corresponding end of the upper waveguide terminates at an input facet. The combination of a gain section and the monolithically tunable wavelength selective coupler forms a broadly tunable laser which is an important source of optical energy for a number of applications such as wavelength division multiplexed networks and switching systems. The laser frequency is determined by that wavelength .lambda.o which satisifies the forward coupling phase match condition, .lambda.g=.LAMBDA..vertline.N.sub.2 -N.sub.1 .vertline. of the coupler where .LAMBDA. is the coarse grating period and N.sub.1, N.sub.2 are the effective indices of the two waveguides. Wavelengths which are not coupled from the upper waveguide to the lower waveguide are attenuated in the optical signal absorbing means. Tuning of the laser wavelength is achieved by either injecting current into or applying a reverse bias voltage to the upper waveguide to decrease or increase its index respectively and change the coupled wavelength.
摘要:
A light transmitter comprising a distributed Bragg reflector laser and mode stabilization feedback means is described for maintaining the laser in single longitudinal mode operation.
摘要:
Disclosed is a method of fabricating an optical waveguide device including the steps of forming a mask over a waveguide core material layer so as to leave a portion of the layer exposed, and exposing the structure to an oxidizing environment to form an oxide layer on the waveguide core material layer at least in the exposed portion thereby defining the lateral dimension of the waveguide core. The resulting waveguide core has extremely smooth surfaces for low optical losses.
摘要:
A fiber laser or fiber amplifier uses resonant pumping of the gain medium by providing a pump resonator that establishes a resonator cavity at the pump wavelength which includes the pumped gain medium. The pump resonator may be of a distributed feedback (DFB) or a distributed Bragg reflector (DBR) type construction, and may be combined with signal reflection apparatus of either DFB or DBR type construction that provides oscillation of the desired laser output wavelength. If used without a signal reflection apparatus, the invention may be operated as a resonant pumped fiber amplifier. Resonant pumped lasers may be arranged in series to provide a laser apparatus with a selectable output wavelength. The different laser stages each provide resonance for a different pump wavelength, and each provide resonance for a different signal wavelength. Thus, a particular pump wavelength input to the series arrangement only resonates in one of the laser stages, and therefore only pumps the gain medium of that stage, allowing it to output its unique signal wavelength. The output signals from each laser stage may be coupled out of the series arrangement with wavelength selective optical couplers, each associated with a different laser stage.