Bandwidth9, Inc.

University of California

Bandwidth Unlimited, Inc.

Gabriel S Li

Wupen Yuen

Constance J Chang-Hasnain

Rang-Chen Yu

Peter Kner

Philip Worland

D Philip Worland

Renato Dato

Contance J Chang-Hasnain

Constance J Chang-Hasnian

A monolithic long-wavelength vertical optical cavity device built up along a vertical direction. The device, when designed as a surface emitting laser, has a bottom Distributed Bragg Reflector (DBR), an active region consisting of active bulk medium or quantum wells, a current confinement layer next to the active layer, and a top DBR. The bottom DBR and the active region are lattice matched to the lattice defining material, while the top DBR is lattice relaxed. The design achieves high reflectivity, low absorption and diffraction loss. The design also ensures low production cost due to low precision requirement and wafer size production. The device can be used as a light detector when the active region is replaced by a spacer or a optical filter.

Lattice-relaxed vertical optical cavities

A tunable semiconductor laser system includes a laser with a semiconductor active region positioned between upper and lower confining regions of opposite type semiconductor material. First and second reflective members are positioned at opposing edges of the active and confining regions. A wavelength tuning member and a temperature sensor are coupled to the laser. A control loop is coupled to the temperature sensor and the tuning member. In response to a detected change in temperature the control loop sends an adjustment signal to the tuning member and the tuning member adjusts a voltage or current supplied to the laser to provide a controlled output beam of selected wavelength.

Tunable semiconductor laser system

A multiplexer for a wavelength division multiplexed optical communication system includes an optical circulator with at least first, second, third and fourth circulator ports. An optical fiber with a first optical transmission path is coupled to the first circulator port and carries a wavelength division multiplexed optical signal that includes signals,. A second optical transmission path is in optical communication with the second circulator port. A first laser is coupled to the second optical transmission path. The first laser reflects the,signals and adds a signal,. A control loop is coupled to the first laser. In response to a detected change in temperature the control loop sends a signal to adjust a voltage or current supplied to the first laser and provide a controlled frequency and power of an output beam. A third optical transmission path is in optical communication with the third circulator port and transmits the signals,and the signals,that are received from the optical circulator. A fourth optical transmission path is in optical communication with the fourth optical circulator port. The fourth optical transmission path is positioned after the second optical transmission path and before the third optical transmission path. A first optoelectronic device is coupled to the fourth optical transmission path.

A monitoring and control assembly for an optical system includes a tunable laser. The laser generates a divergent output beam along an optical axis. A first photodetector is provided. A wavelength selective filter is tilted at an angle relative to the optical axis that provides an angular dependence of a wavelength reflection of the wavelength selective filter and directs the reflected output beam towards the first photodetector.

Monitoring and control assembly for wavelength stabilized optical system

A monolithic vertical optical cavity device built up along a vertical direction. The device has a bottom Distributed Bragg Reflector (DBR), a Quantum Well (QW) region consisting of least one active layer grown on top of the bottom DBR by using a Selective Area Epitaxy (SAE) mask such that the active layer or layers exhibit a variation in at least one physical parameter in a horizontal plane perpendicular to the vertical direction and a top DBR deposited on top of the QW region. A spacer is deposited with or without SAE adjacent the QW region. The device has a variable Fabry-Perot distance defined along the vertical direction between the bottom DBR and the top DBR and a variable physical parameter of the active layer. The varying physical parameter of the active layers is either their surface curvature and/or the band gap and both of these parameters are regulated by SAE. The monolithic vertical cavity device can be used as a Vertical Cavity Surface Emitting Laser (VCSEL) or a Vertical Cavity Detector (VCDET).

Vertical optical cavities produced with selective area epitaxy

The present invention provides multiple-wavelength vertical-cavity surface-emitting laser (&ldquo;MW-VCSEL&rdquo;) arrays. These arrays are fabricated in a molecular beam epitaxy system or the like using two patterned-substrate growth techniques. The growth techniques can be used with an in-situ laser reflectometry. In one embodiment, a temperature dependent growth rate to create the devices is provided. In an alternative aspect, uniform growth is performed followed by a temperature-dependent desorption technique. These techniques provided desired wavelength span and desired characteristics.

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Daly City, CA, United States of America

Gabriel S Li