Photonics & Imaging

Specialized mixed-signal (radio frequency and digital) hardware and processing techniques are employed to enable processing of the multi-GHz signal bandwidth, along with the instruction of an inter-symbol guard time (ISGT) to facilitate synchronization to the received pulse-position modulation (PPM) signal.

The Laser Interferometry Space Antenna’s (LISAs) scientific mission to detect gravity waves demands stringent noise limits on the system components, especially the large-area quad photoreceiver front end, for ultra-high-precision (≈10 pm/Hz1/2) distance...

Wavefront sensing is a process by which optical system errors are deduced from the aberrations in the image of an ideal source. The method has been used successfully in near-normal incidence, but not for grazing incidence systems. This innovation highlights the ability to examine...

RxGen is a prescription generator for JPL’s in-house optical modeling software package called MACOS (Modeling and Analysis for Controlled Optical Systems), which is an expert optical analysis software package focusing on modeling optics on dynamic structures, deformable optics, and controlled...

Theodolites are a common instrument in the testing, alignment, and building of various systems ranging from a single optical component to an entire instrument. They provide a precise way to measure horizontal and vertical angles. They can be used to align multiple objects in a desired way...

Digitally enhanced heterodyne interferometry (DI) is a laser metrology technique employing pseudo-random noise (PRN) codes phase-modulated onto an optical carrier. Combined with heterodyne interferometry, the PRN code is used to select individual signals, returning the inherent interferometric sensitivity...

The dark current of a transferred-electron photocathode with an InGaAs absorber, responsive over the 0.9-to-1.7-μm range, must be reduced to an ultralow level suitable for low signal spectral astrophysical measurements by lowering the temperature of the sensor incorporating the...

Means have been developed for enabling fiber optic cables of the Laser Induced Breakdown Spectrometer instrument to survive ground operations plus the nominal 670 Martian conditions that include Martian summer and winter seasons. The purpose of this development was to...

A simple new way of obtaining absolute wavefront measurements with a laboratory Fizeau interferometer was recently devised. In that case, the observed wavefront map is the difference of two cavity surfaces, those of the mirror under test and of an unknown reference surface on...

A solid-state light source combines an array of light-emitting diodes (LEDs) with advanced electronic control and stabilization over both the spectrum and overall level of the light output. The use of LEDs provides efficient operation over a wide range of wavelengths and power levels, while electronic...

A conceptual design has been developed for a miniature laser magnetometer (MLM) that will measure the scalar magnitude and vector components of near-Earth magnetic fields. The MLM incorporates a number of technical innovations to achieve high-accuracy and high-resolution performance while significantly reducing the size...

NASA satellites measure vector magnetic fields around planets to learn about the geology of the planets. Existing fluxgate magnetometers drift as a result of temperature and aging. A magnetometer whose calibration was stable would improve investigations of planets and the solar system.

The fabrication of large optics is traditionally a slow process, and fabrication capability is often limited by measurement capability. While techniques exist to measure mirror figure with nanometer precision,...

An optical design is presented for a measurement system used to assess the impact of surface errors originating from diamond turning artifacts. Diamond turning artifacts are common by-products of optical surface shaping using the diamond turning process (a...

A system was designed to automate cryogenically cooled low-noise amplifier systems used in the NASA Deep Space Network. It automates the entire operation of the system including cool-down, warm-up, and performance monitoring. The system is based on a single-board computer with custom software and...

A multi-beam, multi-color, polarized laser transmitter has been developed for mapping applications. It uses commercial off-the-shelf components for a low-cost approach for a ruggedized laser suitable for field deployment.

An optical link from Earth to an aircraft demonstrates the ability to establish a link from a ground platform to a transceiver moving overhead. An airplane has a challenging disturbance environment including airframe vibrations and occasional abrupt changes in attitude during flight. These...

This circuit design implements an integrator intended to allow digitization of the energy output of a pulsed laser, or the energy of a received pulse of laser light. It integrates the output of a detector upon which the laser light is incident. The integration is performed constantly, either by...

A specially designed barrier (B) is inserted at the n-pi junction [where most G-R (generation-recombination) processes take place] in the standard n-pi-p structure to substantially reduce generation-recombination dark currents. The resulting n-B-pi-p structure also has reduced tunneling dark currents, thereby...

Current fiber switch technologies use mechanical means to redirect light beams, resulting in slow switch time, as well as poor reliability due to moving parts wearing out quickly at high speeds. A non-mechanical ability to switch laser output into one of multiple fibers within a fiber...

The determination of radius of curvature (ROC) of optics typically uses either a phase measuring interferometer on an adjustable stage to determine the position of the ROC and the optics surface under test. Alternatively, a spherometer or a profilometer are used...