Abstract:
A waveform synthesizer comprising for synthesizing RF lightwave waveforms in the optical domain. These waveforms are constructed by generating their constituent Fourier frequency components or tones and then adjusting the amplitudes of those frequency components or tones. The apparatus includes: a RF-lightwave frequency-comb generator; and a multi-tone, frequency selective amplitude modulator coupled to the RF-lightwave frequency-comb generator for generating a continuous-wave comb comprising a set of RF tones amplitude modulated onto a lightwave carrier.
Abstract:
A spread spectrum waveform generator has a photonic oscillator and an optical heterodyne synthesizer. The photonic oscillator is a multi-tone optical comb generator for generating a series of RF comb lines on an optical carrier. The optical heterodyne synthesizer includes first and second phase-locked lasers, where the first laser feeds the multi-tone optical comb generator and the second laser is a single tone laser whose output light provides a frequency translation reference. At least one photodetector is provided for heterodyning the frequency translation reference with the optical output of the photonic oscillator to generate a spread spectrum waveform. A receiver pre-processor may be provided to operate on the spread spectrum waveform.
Abstract:
A multi-tone photonic oscillator comprises a laser; an optical modulator coupled to the laser; and a delay line and a photodetector coupled to the optical modulator for generating a delayed electrical signal representation of the output of the optical modulator; wherein the optical modulator being responsible for the delayed electrical signal for generating multiple tones where the frequency intervals of the tones is a function of the amount of delay imposed by the delay line.
Abstract:
An apparatus and methods for encoding and decoding data are disclosed. The method for transmitting and receiving data allows for coding and decoding each bit of data with a different code. The transmitter and receiver devices allow encoding and decoding, respectively, each bit of data with different a code.
Abstract:
A vertical cavity modulator/detector (VCMD) device and a method for modulating and detecting light are disclosed. The VCMD device contains an n-type contact layer, a transparent tuning layer, a multiple quantum well structure, a p-type contact layer, a low reflectance mirror arranged to be an input for a light that is to be modulated and a light that is to be detected, and a high reflectance mirror, wherein said n-type contact layer, said transparent tuning layer, said multiple quantum well structure and said p-type contact layer are arranged in a stack between said low reflectance mirror and said high reflectance back mirror.
Abstract:
An agile spread spectrum waveform generator comprises a photonic oscillator and an optical heterodyne synthesizer. The photonic oscillator comprises a multi-tone optical comb generator for generating a series of RF comb lines on an optical carrier. The optical heterodyne synthesizer includes first and second phase-locked lasers; the first laser feeding the multi-tone optical comb generator and the second laser comprising a rapidly wavelength-tunable single tone laser whose output light provides a frequency translation reference. A photodetector is provided for heterodyning the frequency translation reference with the optical output of the photonic oscillator to generate an agile spread spectrum waveform.
Abstract:
A spread spectrum waveform generator has a photonic oscillator and an optical heterodyne synthesizer. The photonic oscillator is a multi-tone optical comb generator for generating a series of RF comb lines on an optical carrier. The optical heterodyne synthesizer includes first and second phase-locked lasers, where the first laser feeds the multi-tone optical comb generator and the second laser is a single tone laser whose output light provides a frequency translation reference. At least one photodetector is provided for heterodyning the frequency translation reference with the optical output of the photonic oscillator to generate a spread spectrum waveform. A receiver pre-processor may be provided to operate on the spread spectrum waveform.
Abstract:
A vertically integrated optical phased array has an array of a plurality of vertical cavity surface emitting lasers disposed in an aperiodic arrangement thereof, the plurality of vertical cavity surface emitting lasers having light emitting ports disposed parallel to one another. An array of a plurality of vertical cavity phase modulators disposed in the same aperiodic arrangement as the array of the plurality of vertical cavity surface emitting lasers, with individual modulators of said array of a plurality of vertical cavity phase modulators each being disposed in optical alignment with an injection port of a corresponding one of said plurality of vertical cavity surface emitting lasers. An array of a plurality of laser ports, fed by a master laser, are disposed in the same aperiodic arrangement as the array of the plurality of vertical cavity surface emitting lasers, the master laser providing, in use, injection beamlets, each injection beamlet, in use, injection locking a corresponding one of said plurality of vertical cavity surface emitting lasers via a corresponding one of said plurality of vertical cavity phase modulators.
Abstract:
Disclosed is a method and apparatus for optically modulating and transmitting source data. An optical comb comprising optical tones having a frequency spacing equal to Δf is generated by an optical comb generator. Selected ones of the optical tones in the optical comb are modulated according to the source data to produce a comb of modulated optical tones. At least one optical tone in the optical comb is frequency shifted by a frequency less than Δf to produce a frequency shifted unmodulated optical reference tone. The optical comb, the frequency shifted unmodulated optical reference tone and the comb of modulated tones are multiplexed onto at least one optical path.
Abstract:
In one implementation of the present invention, a method is provided for frequency tuning of a photonic oscillator. The method includes supplying an optical signal, for example laser light, which is modulated, delayed, and then converted to an electrical signal. The electrical signal is amplified, and used in modulating the optical signal. With this implementation, the frequency of the an output signal of the photonic oscillator is adjusted by adjusting a bias voltage of the amplifier. In some implementations, adjusting the frequency of the output signal further includes using a frequency lock loop circuit. In some implementations, adjusting the frequency of an output signal of the photonic oscillator further comprises adjusting at least one of an phase shifter in series with the amplifier, an optical fiber stretcher, or a bias voltage of a second amplifier. In one embodiment of the present invention, a photonic oscillator is provided including a laser and an optical modulator coupled to the laser. A lightwave delay path is coupled to the optical modulator. In some embodiments, dual lightwave delay paths are provided, such as a long loop delay path and a short loop delay path. A photodetector is coupled between the lightwave delay path and an amplifier. Typically, a bandpass filter is coupled between the amplifier and the modulating input of the optical modulator. A control circuit coupled to the amplifier is constructed so as to be capable of adjusting a bias power to the amplifier so as to shift a frequency of an output of the photonic oscillator. In some embodiments, the control circuit may include a frequency lock loop circuit.