Lucent Technologies Inc.

Avago Technologies General IP (singapore) Pte. Ltd.

Triquint Technology Holding Co.

Agere Systems Optoelectronics Guardian Corp.

At+t Corp.

Acacia Communications, Inc.

Acacia Technology, Inc.

Leonard Jan-Peter Ketelsen

John Evan Johnson

Charles H Joyner

Long L Chen

David Alan Ackerman

Sharon K Sputz

Christopher Richard Doerr

Uziel Koren

Lawrence Warren Stulz

Abdallah Ougazzaden

Sung-Nee George Chu

Richard Bendicks Bylsma

Liming Zhang

Dirk Joachim Muehlner

Mark S Hybertsen

Justin Larry Peticolas

Harald F Hess

Julian Bernard Donald Soole

Mary L Gray

Eric J Dean

Rudolph Conrad Schweizer

Janet L Lentz

Aspects of the present disclosure are directed to a photonic integrated circuit (PIC) having a resistivity-engineered substrate to suppress radio-frequency (RF) common-mode signals. In some embodiments, a semiconductor substrate is provided that comprises two portions having different levels of resistivity to provide both suppression of common mode signals, and reduction of RF absorption loss for non-common mode RF signals. In such embodiments, a bottom portion of the semiconductor substrate has a low resistivity to suppress common mode via RF absorption, while a top portion of the semiconductor substrate that is adjacent to conductors in the IC has a high resistivity to reduce RF loss.

Resistivity engineered substrate for RF common-mode suppression

A tunable semiconductor laser incorporates a light generating structure in which light is generated and amplified by stimulated emission. The generated light is evanescently coupled into a first resonator of a first resonant optical reflector where the light is reflected back and forth between two end mirrors. A portion of this light, which is characterized by a series of resonant wavelengths, is evanescently coupled back into the light generating structure. One or more of the resonant wavelengths can be changed by modifying an optical path length of the first resonator. The tunable semiconductor laser further includes a second resonant optical reflector having a second resonator. The second resonator interacts with the light generating structure in a manner similar to the first resonator. A desired beat wavelength can be obtained by modifying the optical path length in one or both resonators.

Wavelength tunable semiconductor laser

A wavelength division multiplexer utilizes an optical source in the form of at least two separate laser array components, each laser array component including a group of laser diodes operating at wavelengths that are spaced by a multiple of the pre-defined channel spacing of the multiplexer. This optical source thus generates a plurality of non-sequential optical signals that need to be re-ordered at some point along the signal path so that all of the signals are multiplexed onto a single output signal path. The multiplexer utilizes an arrayed waveguide grating (AWG) to combine the various optical signals, with a specialized apparatus for re-ordering the non-sequential wavelengths of the propagating plurality of N optical signals disposed either at the input or output of the AWG.

Planar lightwave circuit optical multiplexer for non-sequential wavelength channels

The present invention provides an optical device and a method of manufacture thereof. In one embodiment, the method of manufacturing the optical device may include isolating an end of a first layer from a cladding layer located over a mesa structure that has been formed from a substrate. The end of the first layer may be isolated from the cladding layer by encapsulating the end between second and third layers located adjacent the mesa structure.

Optical device and method of manufacture thereof

A process evaluates an aging property of a distributed Bragg reflector (DBR) laser. The process includes illuminating a Bragg grating of the distributed Bragg reflector (DBR) laser with light while the DBR laser is both supplied a tuning current and not lasing. The process also includes performing an action to the DBR laser responsive to a wavelength of a Bragg peak in a portion of the light reflected by the Bragg grating and a value of the tuning current supplied during the illuminating.

Aging in tunable semiconductor lasers

The invention in one aspect is an optical modulator which includes a waveguide region of semiconductor material. In order to achieve a gradual, essentially linear transfer function, the bandgap of the waveguide region is graded along the direction of light propogation or perpendicular thereto. In accordance with another aspect, the invention is an electroabsorption modulated laser where the portion of the waveguide region defining the modulator has a graded bandgap. In accordance with a method aspect, the waveguide region of the modulator is grown using a mask having a varying width to achieve the graded bandgap.

Modulator for analog applications

A hybrid integrated optical transmitter comprising a wavelength selectable laser (WSL) source coupled to an optical amplifier/modulator has been realized. Disposed between the optical combiner and the optical amplifier/modulator is an &ldquo;optical isolator.&rdquo; The optical isolator includes at least a Faraday rotator and, either solely or in combination with a single polarizer and/or half-wave plate is used to selectively rotate and pass polarized light egressing from the wavelength selectable laser source. Optical isolation is achieved by the egressing radiation from and back reflections incident on the laser source being at two mutually exclusive orthogonal polarization states or by the reflections being totally extinguished. Advantageously, the laser source is unresponsive to orthogonally polarized light, and hence any unwanted back reflections do not substantially affect the operating characteristics of the laser(s). Optical isolation may be further improved, however, with the use of an additional polarizer positioned in front of the Faraday rotator to totally extinguish the polarized back reflections. Preferably, a latching Faraday rotator is used. As such, permanent magnets are not needed to maintain the latching Faraday rotator in its saturated state, and substantially reduces cost, size and complexity of the transmitter package. The wavelength selectable laser source is integrated on a single substrate with an optical combiner that directs the radiation to the optical amplifier/modulator, which is integrated on a second substrate. Alternatively, the laser source and optical combiner may be integrated on different substrates.

Hybrid integration of a wavelength selectable laser source and optical amplifier/modulator

A micro-photoreflectance technique has been developed for performing non-destructive analysis of III-V optoelectronic devices. By using a significantly reduced spot size (for example, 10 micrometers), various compositional features of the device may be analyzed and the Franz-Keldysh oscillations appearing in the micro-photoreflectance wavelength spectra (such as those beyond the barrier/SCL wavelength in an EML structure) may be analyzed to provide information regarding the physical characteristics of the device, such as the electric field and p-i junction placement within an exemplary EML device structure.

Photoreflectance spectral analysis of semiconductor laser structures

A method of fabricating an expanded beam optical waveguide device (e.g., a laser), comprises the steps of (a) forming a first semiconductor waveguide region having first and second sections of different thickness and an intermediate vertical taper section of varying thickness coupling the first and second sections to one another, the first waveguide region being effective to expand the size of the beam as it propagates from the first section to the second section, (b) forming a second semiconductor region (e.g., a laser active region) on the first waveguide region, (c) etching the second region so as to form an essentially vertical first surface of length A-B which extends obliquely across the propagation axis of the device, (d) forming a third semiconductor region (e.g., a cladding region) on the second region and over the first surface, and (e) etching an elongated mesa along the axis, the mesa extending through at least the second region and the first surface so as to form a second waveguide region having an oblique, essentially second vertical surface which has a length a-b&lt;A-B and which is a subsection of the first surface, the second surface forming an asymmetric horizontal taper effective to optically couple the beam between the second waveguide region and the first waveguide region. Also described is a monolithically integrated optical amplifier and electroabsorption modulator with a dual waveguide expanded beam device fabricated by the inventive method.

Method of fabricating an expanded beam optical waveguide device

A DFB laser with improved loss grating is disclosed. The grating contains periodically patterned first and second semiconductor layers that are embedded in semiconductor material of composition selected to provide relatively low loss for the laser radiation. The composition of the first layer is selected to provide a relatively high refractive index and loss for the laser radiation, and the composition of the second layer is selected to provide relatively low refractive index and loss for the laser radiation. The thicknesses of the first and second layers are selected such that the real part of the coupling constant .vertline..kappa.'.vertline. is less than the imaginary part of the coupling constant .vertline..kappa.'.vertline.. In preferred embodiments .vertline..kappa.'.vertline..ltoreq.0.5.vertline..kappa.'.vertline., even.ltoreq.0.2.vertline..kappa.'.vertline..

Growing community of inventors

Clinton, NJ, United States of America

Leonard Jan-Peter Ketelsen