摘要:
The present invention describes methods and apparatus for reliably assuring that correct mirror currents are selected during a channel switch to achieve the desired wavelength channel, based on feedback from either internal or external means combined with a mode map obtained at a time zero calibration.
摘要:
Controller calibration methods for use with sampled grating distributed Bragg reflector SGDBR laser (102) is presented. An exemplary method includes conducting a two-dimensional mirror current scam of each front mirror current setting and back mirror current setting for a sampled grating distributed Bragg reflector SGBDR laser(102) to produce laser setting data corresponding to each front mirror current setting and back mirror current setting to generate a reference optical signal (114) of the SGDBR laser (102). A channel operating point is determined for each channel within the two-dimensional scan data. A fix up of the operating point to substantially minimize wavelength and power error can also be performed. A two-dimensional control surface is characterized at the channel operating point for each channel. A lookup table for controlling the SGDBR (102) laser is generated from the operating point currents, locker values and two-dimensional control surface data from each channel.
摘要:
A tunable laser is disclosed including a gain section for creating a light beam over a bandwidth, a phase section for controlling the light beam around a center frequency of the bandwidth, a waveguide for guiding and reflecting the light beam in a cavity including a relatively low energy bandgap separate-confinement-heterostructure (SCH), a front mirror bounding an end of the cavity and a back mirror bounding an opposite end of the cavity wherein gain is provided by at least one of the group comprising the phase section, the front mirror and the back mirror.
摘要:
A Vertical-Cavity Surface-Emitting Laser (VCSEL) is disclosed, comprising an optical cavity bounded by a top mirror and a bottom mirror, wherein the top mirror has multiple layers of alternating refractive index, of which the bottom three or more layers of the top mirror are deep oxidation layers having an increased oxidation length, a light emitting active region between the top mirror and the bottom mirror, and an aperture with tapered edges between the active region and the top mirror, wherein the aperture has a thickness, a taper length, an oxide aperture length, a taper angle, and an aperture opening diameter designed to reduce an optical mode's diameter without significantly increasing the optical mode's round trip scattering loss.
摘要:
The present invention discloses a device and a method for producing an oxidizable digital alloy that is sufficiently strain-compensated to provide for substantially defect-free growth on indium phosphide. The device comprises a layer of semiconductor material, a first layer, and a second layer. The first layer is indium arsenide and is coupled to the layer of semiconductor material, wherein the first layer of indium arsenide is under a compressive strain by a lattice mismatch between the layer of semiconductor material and the first layer of indium arsenide. The second layer is aluminum arsenide and is coupled to the layer of indium arsenide, wherein the second layer of aluminum arsenide is under a tensile strain by a lattice mismatch between the second layer and the first layer. The first layer and the second layer comprise a digital alloy of aluminum indium arsenide, and create a quasi-strain-compensated substantially defect-free alloy on the layer of semiconductor material therein. A superlattice period of the first layer of indium arsenide and a second layer of aluminum arsenide is selected to allow an oxide of desired depth to be produced from the digital alloy.
摘要:
A low cost, high speed WDM optical link which employs a circular array of VCSEL emitters directly coupled to a multi-mode fiber through which multiple simultaneously optical transmissions are sent to an optical detector comprising a circular array of RCPD detectors receiving the multiple simultaneous transmissions. The emitters and detectors within each array are fabricated with a double-absorber design which avoids position sensitivity related to the cavity standing wave and eliminates the need for in-situ cavity-mode adjustment. In addition, a coupled-cavity structure is presented to achieve passbands with flat tops and steep sides to approach the ideal square-shape photoresponse and to ensure proper channel alignment.
摘要:
An improvement for allowing selective tuning of the emitted beam over a broad bandwidth to a diode laser having an active section for creating a light beam by spontaneous emission over a bandwidth around some center frequency and for guiding and reflecting the light beam between a pair of mirrors bounding the active on respective ends thereof to create an emitted beam of laser light. The mirrors each have narrow, spaced reflective maxima with the spacing of the reflective maxima of respective ones of the mirrors being different whereby only one the reflective maxima of each of the mirrors can be in correspondence and thereby provide a low loss window at any time. The preferred mirrors each include a plurality of discontinuities to cause the narrow, spaced reflective maxima wherein the spacing of the discontinuities of one mirror is different from the spacing of the discontinuities of the other mirror so as to cause the wavelength spacing of the maxima to be different. Additionally, the preferred embodiment includes a vernier circuit operably connected to the mirrors for providing an electrical signal to the mirrors which will cause continuous tuning within a desired frequency band, an offset control circuit operably connected to the mirrors for providing a voltage signal to the mirrors which will shift the reflective maxima of the mirrors into alignment at a desired frequency mode, and a phase control circuit for adjusting the laser mode wavelength to be in correspondence with the low loss window.
摘要:
Highly reproducible, optically flat mirror facets are created by contacting a predetermined area of the InGaAsP/InP heterostructure system with a chemical etchant for a time period sufficient to expose a substantially vertical crystallographic surface throughout the entire heterostructure system. Contact of the exposed surface with HCl causes a preferred crystallographic plane to be exposed as an optically flat mirror facet.
摘要:
Grating resonators for surface acoustic waves or surface optical waves are coupled in cascade via a track changer external to the resonator cavities. At least one grating of each resonator is partially transmissive in the resonant band, allowing the interchange of energy therebetween via the track changer. The track changer is comprised of either two or three reflective racks angled such that the energy reflected therein propagates along zero-temperature-coefficient paths. The three-rack, three-bounce U-path filter used as a track changer minimizes resonant energy losses due to variations in reflected wave angles from their designed values.
摘要:
A tunable laser source (10) with an integrated optical modulator (20). The laser source (10) is a widely tunable semiconductor laser that is comprised of an active region on top of a thick low bandgap, waveguide layer (22), wherein both the waveguide layer (220) and the active region are fabricated between a p-doped region and an n-doped region. An electro-absorption modulator (20) is integrated into the semiconductor laser (10), wherein the electro-absorption modulator (20) shares the waveguide layer (22) with the semiconductor laser.