Coretek, Inc.

Nortel Networks Corporation

Reich L Watterson

Parviz Tayebati

Kevin John McCallion

Yakov Kogan

Donald L McDaniel, Jr

Daryoosh Vakhshoori

Don W McDaniel

Rong Huang

Donald McDaniel

Wavelength reference apparatus for use in calibrating a tunable Fabry-Perot filter or a tunable VCSEL, whereby the device may be tuned to a precise, known wavelength, the wavelength reference apparatus comprising an LED, where the LED is chosen so as to have an emission profile which varies with wavelength; an etalon, where the etalon is chosen so as to have a transmission profile which comprises a comb of transmission peaks, with each transmission peak occurring at a precise, known wavelength; and a detector for detecting the light emitted by the LED and passing through the etalon; whereby when a tunable Fabry-Perot filter or tunable VCSEL is positioned between the etalon and the detector, and the device is swept through its tuning range by varying the tuning voltage applied to the device, the known transmission wavelengths established by the LED and the etalon can be correlated to counterpart tuning voltages of the device, whereby to calibrate the device.

Single-etalon, multi-point wavelength calibration reference

A method and apparatus is provided for calibrating a Fabry-Perot etalon based optical measurement system. The calibration is performed by analyzing the shape of transmission peaks output from the etalon in response to a known optical signal and using that information, along with a formula that approximates the response of the etalon, to perform the calibration.

Method and apparatus for calibrating a fabry-perot interferometer based measurement system

According to an aspect of the present invention, a power detector including a photodiode and a logarithmic transimpedance amplifier is mounted inside a hermetically sealed package in such a way that the photodiode and the logarithmic transimpedance amplifier are located on the same thermally conductive substrate.

Wide dynamic range optical power detector

A wavelength reference device for tuning a tunable Fabry-Perot filter and/or a tunable VCSEL to a desired frequency, where the device uses a modified Michelson interferometer to generate a series of reference frequencies

Wavelength reference device

A wavelength reference device for tuning a tunable Fabry-Perot filter and/or a tunable VCSEL to a desired frequency, where the device uses a Fizeau interferometer and a position sensitive detector, with the position sensitive detector being used to measure the location of the maximum reflected power from the interferometer, whereby to determine the wavelength of laser radiation for tuning the device.

An optical fiber wavelenght reference device for tuning a tunable Fabry-Perot filter and/or a tunable VCSEL to a desired frequency, where the device uses a fiber etalon to generate a pattern of reference frequencies against which the device is tuned.

Optical fiber wavelength reference device

A compact wavelength monitoring and control assembly for a narrow band source is provided comprising a narrow bandpass, wavelength selective transmission filter element, of Fabry-Perot structure, through which two collimated beams from a laser source are directed onto two photodetectors. The differential output of the two photodetectors is used in a feedback loop to stabilize the source to the desired wavelength. Through the dependence of the wavelength transmission of the Fabry-Perot etalon on angle and physical parameters, a wavelength variation of the source is converted into a transmission loss, which is different for the detectors, so that the wavelength change is detected by changes in the signals output from the detectors. Through the controlled variation of the source wavelength in the vicinity of the transmission maximum of the etalon, the absolute frequency of the Fabry-Perot locking point may be confirmed by the variation of the ratio of the detector signals.

Single etalon optical wavelength reference device

A compact wavelength monitoring and control assembly for a narrow band (i.e., laser) source is provided, comprising two narrow bandpass, wavelength selective transmission filter elements of Fabry-Perot structure through which two separate collimated beams from a laser source are directed onto two photodetectors. The spacing of the multiple transmission maxima for one etalon is chosen to match that of the desired set of frequencies to be used for locking purposes. The spacing of the transmission maxima for the second etalon is used, in combination with a dielectric filter, to generate a wavelength fiducial to denote an absolute frequency. The spacing of the second etalon is chosen to be much wider than the frequency grid etalon. A control circuit processes the simultaneously acquired signals from the two detectors as the laser wavelength is varied. The device functions as an optical wavelength discriminator in which the detectors convert optical energy to current (or voltage) for a feedback loop for controlling the laser source. Any one of a large number of discrete, predetermined wavelengths may be chosen for locking using the same device. The system is compact and may be packaged within the same temperature controlled laser assembly for maximum performance and minimum circuit board space requirements.

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Lexington, MA, United States of America

Reich L Watterson