Abstract:
In a method and apparatus for converting optical wavelength division multiplexed channels to wireless channels, the information carrying optical carriers are first de-multiplexed and each optical carrier is then extracted from the data using an optical channelizing technique. The optical frequency of each of the extracted optical carriers is then shifted by an amount equal to the desired wireless carrier frequencies in the broadband wireless channels. Optical heterodyning of the frequency-shifted extracted lightwave carriers with the original data-containing optical signals, which are mutually in phase coherence, in a photodetector results in a set of wireless carriers each modulated with the data carried by the corresponding optical channel.
Abstract:
A phase shifter comprises a coarse phase tuning arrangement and a fine phase tuning arrangement. The coarse phase tuning arrangement provides a discrete number of phase shifts. The fine phase tuning arrangement includes a RLC network, having a resistor, an inductor and a capacitor. The fine phase tuning arrangement also comprises an optical arrangement for varying the resistance value of the resistor. This phase shifter is able to obtain broadband, continuous 360null phase shifting also at Gigahertz frequencies. It also allows close to linear phase shift versus frequency resulting in true time delay capability, very low insertion loss and high value of maximum phase adjust.
Abstract:
In a method and apparatus for converting optical wavelength division multiplexed channels to wireless channels, the information carrying optical carriers are first de-multiplexed and each optical carrier is then extracted from the data using an optical channelizing technique. The optical frequency of each of the extracted optical carriers is then shifted by an amount equal to the desired wireless carrier frequencies in the broadband wireless channels. Optical heterodyning of the frequency-shifted extracted lightwave carriers with the original data-containing optical signals, which are mutually in phase coherence, in a photodetector results in a set of wireless carriers each modulated with the data carried by the corresponding optical channel.
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:
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 nullf 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 nullf 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:
A method for transferring of individual devices or circuit elements, fabricated on a semiconducting substrate, to a new substrate and placing said devices and elements in predetermined locations on the new substrate. The method comprises shaping the devices and circuits as truncated cones, lifting them off the original semiconducting substrates and depositing them en masse onto the new substrate, followed by their placing into receptors on the new substrate. The new substrate has preliminarily made receptors in a form of a truncated cone and the devices and circuits fill these receptors. Both the receptors and the devices and circuits have metallization contacts enabling to establish electrical contact between them. A method for real-time monitoring and verification of correctness of placement of the devices and circuits into the receptors by applying voltage pulse waveforms and measuring the resulting current pulse.
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 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.