Abstract: A method for reducing surface recombination in an area next to a mesa in devices containing active and passive sections. This is obtained by growing, by metalorganic vapor phase epitaxy (MOVPE), a thin epitaxial layer of material with larger bandgap than a waveguide material and preferably smaller surface recombination rate than the waveguide material. This thin layer is preferably non-intentionally doped to avoid creating a surface leakage path, thin enough to allow for carrier to diffuse to and thermalize in the waveguide layer and thick enough to prevent carriers to tunnel through it.

Abstract: Traveling-wave optoelectronic wavelength conversion is provided by a monolithic optoelectronic integrated circuit that includes an interconnected traveling-wave photodetector and traveling-wave optical modulator with a widely tunable laser source. Either parallel and series connections between the photodetector and modulator may be used. An input signal modulated onto a first optical wavelength develops a traveling wave voltage on transmission line electrodes of the traveling-wave photodetector, and this voltage is coupled via an interconnecting transmission line of the same characteristic impedance to transmission line electrodes of the traveling-wave optical modulator to modulate the signal onto a second optical wavelength derived from the tunable laser. The traveling wave voltage is terminated in a load resistor having the same characteristic impedance as the photodetector and modulator transmission lines.

Abstract: Traveling-wave optoelectronic wavelength conversion is provided by a monolithic optoelectronic integrated circuit that includes an interconnected traveling-wave photodetector and traveling-wave optical modulator with a widely tunable laser source. Either parallel and series connections between the photodetector and modulator may be used. An input signal modulated onto a first optical wavelength develops a traveling wave voltage on transmission line electrodes of the traveling-wave photodetector, and this voltage is coupled via an interconnecting transmission line of the same characteristic impedance to transmission line electrodes of the traveling-wave optical modulator to modulate the signal onto a second optical wavelength derived from the tunable laser. The traveling wave voltage is terminated in a load resistor having the same characteristic impedance as the photodetector and modulator transmission lines.

Abstract: 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.

Abstract: A partially mirrored beam tap for use in wavelength and power monitoring, wherein the partially mirrored beam tap splits off at least two beams from an elliptical Gaussian output beam, wherein a first split-off beam is transmitted to an etalon and one or more first photo-detectors for wavelength monitoring, while a second split-off beam is transmitted to one or more second photo-detectors as a reference and for power monitoring. The partially mirrored beam tap splits off the first and second split-off beams from upper and lower tails of the output beam, wherein upper and lower portions of the partially mirrored beam tap comprise mirrored surfaces that reflect tails of the output beam and a center portion of the partially mirrored beam tap comprises a clear rectangular aperture that passes the output beam.

Abstract: A photonic device designed with an intermittent absorption profile along a waveguide. The absorption profile is divided into low-absorption and high-absorption segments that are distributed axially in order to decrease the maximum local temperature in the device. The distribution of low-absorption segments can be controlled through techniques such as proton implantation or selective-area quantum well intermixing. The lengths of low-absorption and high-absorption segments can be adjusted to optimize heat dissipation along the device length.

Abstract: Traveling-wave optoelectronic wavelength conversion is provided by a monolithic optoelectronic integrated circuit that includes an interconnected traveling-wave photodetector and traveling-wave optical modulator with a widely tunable laser source. Either parallel and series connections between the photodetector and modulator may be used. An input signal modulated onto a first optical wavelength develops a traveling wave voltage on transmission line electrodes of the traveling-wave photodetector, and this voltage is coupled via an interconnecting transmission line of the same characteristic impedance to transmission line electrodes of the traveling-wave optical modulator to modulate the signal onto a second optical wavelength derived from the tunable laser. The traveling wave voltage is terminated in a load resistor having the same characteristic impedance as the photodetector and modulator transmission lines.

Abstract: A controller for use with sampled grating distributed Bragg reflector (SGDBR) lasers is presented. An exemplary controller includes a table of settings representing a control surface, each setting corresponding to a separate operating point of the SGDBR laser, a first mirror current controller and a second mirror current controller. The first mirror controller and the second mirror current controller respectively control a first mirror current and a second mirror current about an estimated extremum point of the control surface to substantially maintain alignment between each of a first mirror and a second mirror, and an associated cavity mode. The first mirror current and the second mirror current can be locked at a substantially fixed distance from the extremum of the control surface.

Abstract: The present invention relates to the tailoring the reflectivity spectrum of a SGDBR by applying digital sampling theory to choose the way each reflector is sampled. The resulting mirror covers a larger wavelength span and has peaks with a larger, more uniform, coupling constant (?) than the mirrors produced using conventional approaches. The improved mirror also retains the benefits of the sample grating approach. Additionally, most of the embodiments are relatively simple to manufacture.

Abstract: 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.

Abstract: 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.

Abstract: Presented herein is an astigmatism correcting coupler. The couplet comprises a collimating lens, a focusing lens, and a power adjusting lens element. The power adjusting lens element may be positioned intermediate the collimating lens and focusing lens, or positioned after the focusing lens element.

Abstract: An open loop controller for use with a sampled grating distributed Bragg reflector (SGDBR) laser is presented. The controller for provides separate inputs to the laser including a front mirror current controlling a front mirror and a back mirror current controlling a back mirror to control, as well as a phase current and a gain current. The open loop controller in accordance with the present invention further includes a lookup table generated to reflect the unique specifications of each SGDBR laser is controlled.

Abstract: An anamorphic prism wavelength locker for a laser output beam, wherein the anamorphic prisms perform beam splitting for wavelength and power monitoring for the output beam, magnification of the output beam, and circularization of an elliptical output beam.

Abstract: A photonic device designed with an intermittent absorption profile along a waveguide. The absorption profile is divided into low-absorption and high-absorption segments that are distributed axially in order to decrease the maximum local temperature in the device. The distribution of low-absorption segments can be controlled through techniques such as proton implantation or selective-area quantum well intermixing. The lengths of low-absorption and high-absorption segments can be adjusted to optimize heat dissipation along the device length.

Abstract: A compensating electrical signal is applied to one or more sections of a laser to over-compensate for chirp from an external modulator employed for intensity modulation. The chirp of the laser is adjustable by design or electrical control.

Abstract: A method for reducing surface recombination in an area next to a mesa in devices containing active and passive sections. This is obtained by growing, by metalorganic vapor phase epitaxy (MOVPE), a thin epitaxial layer of material with larger bandgap than a waveguide material and preferably smaller surface recombination rate than the waveguide material. This thin layer is preferably non-intentionally doped to avoid creating a surface leakage path, thin enough to allow for carrier to diffuse to and thermalize in the waveguide layer and thick enough to prevent carriers to tunnel through it.

Abstract: The invention discloses an optical output power and output wavelength control system for use with a sampled grating distributed Bragg reflector (SGDBR) laser. The optical output power and output wavelength control system for use with a sampled grating distributed Bragg reflector (SGDBR) laser comprises a controller for providing current inputs to the laser controlling the optical output power and output wavelength and an external reference receiving an optical output from the laser and providing a reference output to the control, wherein the controller compares the optical output power and output wavelength of the laser to the reference output and locks the optical output power and output wavelength of the laser to the external reference.

Abstract: A method of generating an optical signal provides a diode laser assembly including an epitaxial structure formed on a substrate. A laser and an amplifier are formed in the epitaxial structure. At least a portion of the laser and amplifier share a common waveguide. A tunable laser output is produced from the laser. The laser output is coupled into the amplifier along the common waveguide. An optical signal is generated from the amplifier.

Abstract: A tunable modulator includes an epitaxial structure formed on a substrate. The epitaxial structure includes a waveguide for light guiding, generally in form of a ridge, a trench for thermal insulation and an integrated heating element which, when a current is passed therethrough, heats the modulator and in turn changes the effective bandgap. This alters the wavelength that is best modulated resulting in a tunable modulator in accordance with the present invention. Literature [1] Beck Mason, Greg A. Fish, Steven P. DenBaars, Larry A. Coldren, “Widely Tunable Sampled Grating DBR Laser with Integrated Electroabsorption Modulator,” IEEE Photonics Technology Letters, vol. 11, no. 6 pp. Jun. 4-6, 1999 FIG. 4. [2] Lucent/Agere Application Note TN00008 on electro-absorption modulators (EML), May 2000.