Blueleaf, Inc.

Picarro, Inc.

Université Joseph Fourier

Alexandre Katchanov

Barbara A Paldus

Daniele Romanini

Arnaud Garnache

Frederic Stoeckel

Bruce A Richman

Jinchun Xie

Marc Levenson

Guido Knippels

Christopher Rella

Robert Lodenkamper

Hoa Pham

Gerald P Coleman

Dmitri Permogorov

Frederick Stoeckel

A tunable laser and laser tuning method based on the use of a tunable etalon in reflection as a mirror within a laser cavity and forming an end reflective surface thereof. The laser emission wavelength is not necessarily at a wavelength of peak etalon reflectivity. A preferred embodiment makes use of a microelectromechanical etalon to tune an external cavity semiconductor.

Laser with reflective etalon tuning element

A tunable laser and laser tuning method based on the use of a tunable etalon in reflection as a mirror within a laser cavity. The laser emission wavelength is not necessarily at a wavelength of peak etalon reflectivity. A preferred embodiment makes use of a microelectromechanical etalon to tune an external cavity semiconductor laser.

An optical fiber transmitter comprises an optically pumped single mode MQW VECSEL for emitting an information-carrying laser beam and has an external cavity length defining a comb of optical modes, each mode corresponding to a channel wavelength of an optical telecommunications system having plural optical channels. A semiconductor structure of the VECSEL has an optical-pump-excited multiple quantum well (MQW) homogeneously broadened gain region active over a band which is less than mode-to-mode spacing, the gain region being tunable to hop from a first mode to an adjacent second mode. A tuning arrangement tunes the VECSEL from mode to mode thereby to select each one of the plural optical channels. An optical modulator adds modulation to a beam emitting from the laser to provide the information-carrying laser beam, and a coupler couples the information-carrying laser beam into an optical fiber of the optical telecommunications system. A calibration method based on detecting inter-mode optical transitions (mode hopping) is described.

Optical transmitter having optically pumped vertical external cavity surface emitting laser

An optical fiber transmitter for emitting an information-carrying laser beam comprises an optically or electrically pumped single mode MQW (multi-quantum well) semiconductor amplifying mirror as a gain medium and a separate external reflector to form a cavity. The external cavity length defines a comb of optical modes, all or a subset of which correspond to channel wavelengths of an optical telecommunications system having plural optical channels. The semiconductor gain element has a homogeneously broadened gain region; a tuning arrangement tunes the laser from mode to mode across the gain region, thereby selecting each one of the plural optical channels. When the maximum gain bandwidth is less than mode-to-mode spacing defined by the cavity, the tuning arrangement includes a means of altering the temperature of the amplifying mirror, thereby translating the frequency of the gain peak from one mode to another. An optical modulator adds modulation to provide an information-carrying laser beam, and a coupler couples the information-carrying laser beam into an optical fiber of the optical telecommunications system. A calibration method based on detecting inter-mode optical transitions (mode hopping) is described. The parameters of the amplifying mirror and tuning arrangement can be adjusted during operation to switch quickly from one cavity mode to another in stepwise fashion.

Optical transmitter comprising a stepwise tunable laser

System and method for simultaneously providing a wavelength spectral distribution and a temporal distribution of an incident light beam. The light beam is received at a wavelength spectral distribution module and is separated into light beam segments corresponding to at least two different wavelengths in a first selected direction transverse to beam propagation direction. The light beam is also received at a temporal distribution module, and segments of the light beam are distributed corresponding to at least two different times at which light in the beam was produced, in a second selected direction that is substantially perpendicular to the first direction. The temporal distribution module may include a rotating segmented mirror.

Spectro-temporal analyzer

A laser suitable for intra-cavity laser absorption spectroscopy and for telecommunication system comprises a Bragg mirror, a multiple quantum well active region and an anti-reflective coating together with a second mirror spaced from the coating to define an external cavity, the free spectral range of the sub-cavity defined by the coating and the active region being less than two times the bandwidth of the coating and the bandwidth of the Bragg mirror being at least as great as the free spectral range of the sub-cavity.

Surface-emitting semiconductor laser

An optical fiber transmitter for emitting an information-carrying laser beam comprises an optically or electrically pumped single mode MQW (multi quantum well) semiconductor amplifying mirror as a gain medium and a separate external reflector to form a cavity. The external cavity length defines a comb of optical modes, all or a subset of which corresponding to channel wavelengths of an optical telecommunications system having plural optical channels. The semiconductor gain element has a homogeneously broadened gain region; a tuning arrangement tunes the laser from mode to mode across the gain region thereby selecting each one of the plural optical channels. When the maximum gain bandwidth is less than mode-to-mode spacing defined by the cavity, that tuning arrangement comprises a means of altering the temperature of the amplifying mirror, thereby translating the frequency of the gain peak from one mode to another. An optical modulator adds modulation to a beam emitting from the laser to provide the information-carrying laser beam, and a coupler couples the information-carrying laser beam into an optical fiber of the optical telecommunications system. A calibration method based on detecting inter-mode optical transitions (mode hopping) is described. The parameters of the amplifying mirror and tuning arrangement can be adjusted during operation to switch quickly from one cavity mode to another in stepwise fashion.

The invention concerns a method for detecting gas traces with a semiconductor laser coupled with an optical resonant cavity containing a species to be analyzed. The laser is coupled with the cavity so that the light is not projected back towards the laser when the cavity is in resonance mode. The laser supplies an amplified and fine-tuned emission on the re-injected frequency and, when a current pulse is applied thereon, its frequency moves from a predetermined initial frequency to a final predetermined frequency. The laser is excited by a first current pulse such that its frequency is sequentially locked on the cavity successive modes. The luminous intensity decreasing time in the cavity is measured at the end of the pulse and the excitation and measurement steps are repeated for successive current pulses, to cover a spectral range to be analyzed.

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Sunnyvale, CA, United States of America

Alexandre Katchanov