Trw Limited

Northrop Grumman Systems Corporation

John C Brock

Lawrence J Lembo

Michael G Wickham

Philip Henry Wisseman

Mark Kintis

Dean Tran

David Lawrence Rollins

Edward A Rezek

Mau-Song Chou

Richard L Davis

Christian L Marquez

Michelle M Hazard

Peter R Pawlowski

Lawrence R Tittle

Scott K Isara

The invention relates to an optical, integrated alignment device for accurately aligning and efficiently coupling energy between in-plane optical devices. A semiconductor substrate is etched to include a groove for an optical fiber and a lens for passing an optical signal from a cut fiber to a photodetector. The etched semiconductor substrate may be used to pass an optical signal from a surface light emitting device to a cut fiber. The end of the optical fiber is cut at a slant that redirects an optical signal from the fiber through the lens or vice-versa. The lens focuses the optical signal onto a target.

Integrated aspheric optical coupler for RF planarized automatic photonics packaging

A system for the remote detection and analysis of trace chemical agents in the air. A beam of electromagnetic radiation is used to radiate a cloud. The radiation energy that is absorbed by the cloud is thermalized by collisional energy transfer between the molecules that absorb the radiation. Increases in the cloud temperature increase the emission intensity of the molecules against the background, resulting in improved detection of the target molecules. A tracking telescope is used to collect the thermal emissions generated by the radiation beam. A spectrometer is used to resolve the emissions from the cloud and generate an emissions spectrum. The wavelength of the electromagnetic radiation can be selected to be in resonance with the absorption lines of water or oxygen molecules in the cloud, or to be in resonance with absorption lines of known target molecules in the cloud to generate the heat.

Remote trace gas detection and analysis

A multispectral imaging system ( ) and method utilize an optical processor ( ) for simultaneously comparing an input wavelength spectrum observed in a single spatial pixel in a scene image from a multispectral imager ( ) with a plurality of template wavelength spectra to find a correlation. The optical processor exploits the three-dimensional attributes of optical correlation to perform massively parallel correlation processing by modulating ( ) respective ones of a plurality of spectral bands of the input wavelength spectrum of an incident light beam ( ) with modulating elements ( ) to alter at least one property of the incident light beam by a value corresponding to the observed intensity of the input spectrum in the respective spectral band. In a disclosed embodiment, the modulated beam is expanded and transited through a spatial light modulator ( ) having a two-dimensional array of modulating elements. Each row of the elements of the array alter the at least one property of the incident light by values corresponding to a particular template wavelength spectrum of a plurality of template wavelength spectra of the modulator. The values corresponding to each template spectrum are the conjugates of the representative values of the modulating elements of the template spectrum of the plurality of template spectra.

Multispectral imaging system and method

A channelizer for signals for optically channelizing RF signals modulated onto an optical carrier by optically separating the RF signals and mapping the RF signals by way of an optically dispersive element, such as a diffraction grating. In an alternate embodiment of the invention, two stages of optical filters elements are provided in series to perform sequential channelization. Bragg reflection gratings are used for coarse filtering into predetermined bands while Fabry-Perot filters tuned to specific sub-bands of the Bragg reflection gratings are used for channelization. In alternate embodiments of the invention, a silica planar waveguide and a optical splitting device, such as a Talbot splitter, are used.

All optical RF signal channelizer

A channelizer for signals for optically channelizing RF signals modulated onto an optical carrier by optically separating the RF signals and mapping the RF signals by way of an optically dispersive element, such as a diffraction grating. In an alternate embodiment of the invention, two stages of optical filters elements are provided in series to perform sequential channelization. Bragg reflection gratings are used for coarse filtering into predetermined bands while Fabry-Perot filters tuned to specific sub-bands of the Bragg reflection gratings are used for channelization. In alternate embodiments of the invention, a silica planar waveguide and an optical splitting device, such as a Talbot splitter, are used.

A system for summing RF modulated optical signals. In order to compensate for performance degradation at the summing junction, the system utilizes four-wave mixing elements to provide the phase conjugates of each of the modulated RF signals. The phase conjugates of the RF modulated optical signals are summed at the summing junction. The use of the phase conjugates of the RF modulated optical signals compensates for optical phase errors known to degrade performance when summing RF modulated optical signals.

R.F. signal summing using non-linear optical phase conjugation

A splitterless optical broadcast switch (110) for routing a plurality of optical carrier signals. The splitterless optical broadcast switch (110) includes an optical source (112) for generating a plurality of unmodulated optical carrier signals. A first stage routing module (114) routes the plurality of unmodulated optical carrier signals. A modulating module (116) receives a plurality of RF input signals and modulates each of the RF input signals onto any number of the unmodulated optical carrier signals to generate a plurality of modulated optical carrier signals. A second stage routing module (118) routes the plurality of modulated optical carrier signals complimentary to the first stage routing module (114). An output module (120) receives the plurality of modulated optical carrier signals such that the optical output from the optical source (112) is paired to a complimentary optical input of the output module (120).

Splitterless optical broadcast switch

An electro-optic modulator and a method for its use, in which an optical carrier is effectively suppressed for transmission of a radio-frequency (rf) modulating signal over an optical communication link, to provide improved demodulator performance. A carrier component is recovered from the modulator, amplified, and reused, to minimize the effect of optical carrier losses. In one embodiment of the invention, a modulator (10) with complementary output ports (20 and 22) generates a carrier-suppressed output (FIG. 2B) containing rf sidebands from one port (20) and a strong carrier component (FIG. 2C) from the other output port (22). The carrier component is filtered in a residual sideband filter (14), amplified in an optical amplifying medium (12) and returned to the modulator (10) as its carrier input. In a second embodiment of the invention, a modulator (30) with a single output port produces rf sidebands and a suppressed carrier component (FIG. 4A), all of which are amplified in an optical amplifying medium (32) and coupled to an optical circulator (34), which, in cooperation with a narrowband filter (36), separates the rf sidebands from the amplified carrier component, the latter being returned to the modulator (30) as the carrier input. In both embodiments, a suppressed-carrier optical signal is obtained for transmission over a communication link, but carrier losses are minimized by recovery and recirculation of the carrier. In an alternate embodiment of the invention (FIG. 5), a second modulator (40) removes any residual rf components and avoids any unwanted cavity resonance.

Optically efficient high dynamic range electro-optic modulator

A photonic interconnect and photonic processing apparatus (10) for use in a communication and data handling satellite (12) is disclosed. The photonic interconnect and photonic processing apparatus (10) includes a receiving device (14) for receiving a plurality of input RF signals. An optical conversion device (28) coupled to the receiving device (14) converts the plurality of input RF signals to a plurality of input optical signals. This plurality of input optical signals are coupled to a plurality of input optical fibers (30). A distribution device (32) optically coupled to the optical conversion device (28) distributes at least one output optical signal from the plurality of input optical signals coupled to the plurality of input optical fibers. The at least one output optical signal is coupled to at least one output optical fiber (30) such that the at least one output optical signal coupled to the at least one output optical fiber (30) is distributed within the communication and data handling satellite (12).

Photonic interconnect and photonic processing for communications and

A wavelength controlled optical true time delay generator (14) utilizes passive switching to direct an optical beam to different length paths depending on the input wavelength. In one embodiment a dispersive element (20) is used to reflect the input beam at different angles depending on the incident wavelength. Different optical paths are then provided for the light reflected at different angles. In another embodiment, an optical fiber (50) is provided with reflective gratings (52), each of which are reflective at different wavelengths. The gratings (52) are positioned at different lengths along the optical fiber (50) to provide for different path lengths of light reflected by the gratings and back down the optical fiber (50) to an optical output (38). The true time delay generator (14) provides for a true time delay of any length in a low loss switching mechanism which is relatively inexpensive and compact.

Wavelength controlled optical true time delay generator

Apparatus, and a corresponding method for it use, for directly modulating an optical carrier with a radio-frequency (rf) electrical signal. A semiconductor electroabsorptive modulator is operated at an optical wavelength and electrical bias voltage carefully selected to provide a near-linear electrical-to-optical transfer characteristic and to keep rf insertion loss low. Further reduction of insertion loss is achieved by use of an extremely short device, or a single quantum well device configuration, or both. Linearity is further optimized by choosing an appropriate combination of optical polarization mode, optical reflectivity of the device facets, and the number and physical properties of multiple quantum wells.

Linear electroabsorptive modulator and related method of analog

Apparatus and a related method for detecting signal photons of a selected wavelength using ionization induced by collisions between atomic or molecular particles. Signal photons raise the energy level of a proportion of particles introduced into a detection chamber to a selected metastable state. Optionally, a pump laser assists in raising the energy level of the particles to a metastable state close to the ionization continuum. Collisions between particles in the selected metastable state and particles of the buffer gas cause ionization of the metastable particles, and a measurable electrical current is obtained, without the need for strong electric fields for ionization, or the need for strong optical fields for photoionization. In a variant form of the invention, a second substance is admitted into the detection chamber. Collisions between the original atomic or molecular particles and particles of the second substance cause ionization of the second substance, again providing a measurable electric current from the free electrons or ions that are produced.

Collisional ionization detected atomic resonance filter

An optical filter and detector, and a related method for its operation, in which signal photons are admitted into a detector cell and selectively excite atoms or molecules of a vapor to a selected metastable state. An illuminating laser then photoionizes a large proportion of the excited atoms or molecules, and the resulting free electrons are collected as a measure of the number of incident signal photons. The initial excitation step to a metastable state is highly sensitive to the wavelength of the signal photons and therefore acts as a narrowband filter.

Photoionization optical filter and detector

Apparatus and a related method for generating a uniphase reference beam from a weak and aberrated input probe beam in an optical system. A portion of the input probe beam is split off and injected into the cavity of a laser, such as a semiconductor diode laser, where four-wave mixing takes place and an amplified input wave or its phase conjugate is output. Because the laser cavity is selected to provide single-mode operation, the laser provides not only amplification but an output that includes a uniphase wave, which may be interfered with the original aberrated input probe beam for purposes of obtaining wavefront information.

Growing community of inventors

Redondo Beach, CA, United States of America

John C Brock