Publications
Adaptive optics program at TMT
Summary
Summary
The TMT first light Adaptive Optics (AO) facility consists of the Narrow Field Infra-Red AO System (NFIRAOS) and the associated Laser Guide Star Facility (LGSF). NFIRAOS is a 60 x 60 laser guide star (LGS) multi-conjugate AO (MCAO) system, which provides uniform, diffraction-limited performance in the J, H, and K...
Chemical aerosol detection and identification using Raman scattering
Summary
Summary
Early warning of the presence of chemical agent aerosols is an important component in the defense against such agents. A Raman spectrometer has been constructed for the purpose of detecting and identifying chemical aerosols. We report the detection and identification of a low-concentration chemical aerosol in atmospheric air using 532-nm...
Silicon photonics devices for integrated analog signal processing and sampling
Summary
Summary
Silicon photonics offers the possibility of a reduction in size weight and power for many optical systems, and could open up the ability to build optical systems with complexities that would otherwise be impossible to achieve. Silicon photonics is an emerging technology that has already been inserted into commercial communication...
Development of CCDs for REXIS on OSIRIS-REx
Summary
Summary
The Regolith x-ray Imaging Spectrometer (REXIS) is a coded-aperture soft x-ray imaging instrument on the OSIRIS-REx spacecraft to be launched in 2016. The spacecraft will fly to and orbit the near-Earth asteroid Bennu, while REXIS maps the elemental distribution on the asteroid using x-ray fluorescence. The detector consists of a...
Simultaneous transmit and receive antenna isolation improvement in scattering environments
Summary
Summary
Simultaneous transmit and receive (STAR) systems require high isolation between the transmitter and receiver to avoid self-interference. Antenna isolation degradation stems from errors in the physical construction and beamformer design, as well as reflections from scattering objects in the environment. An RF canceller subsystem can be inserted at the antenna...
Wideband antenna array for simultaneous transmit and receive (STAR) applications
Summary
Summary
A wideband antenna array for Simultaneous Transmit and Receive (STAR) applications is presented. The design is comprised of a ring array of TEM horns, and a monocone at the array's center. When the array is phased with the first order circular mode, it is isolated from the monocone. Thus, the...
Smart pixel imaging with computational-imaging arrays
Summary
Summary
Smart pixel imaging with computational-imaging arrays (SPICA) transfers image plane coding typically realized in the optical architecture to the digital domain of the focal plan array, thereby minimizing signal-to-noise losses associated with static filters or apertures and inherent diffraction concerns. MIT Lincoln Laboratory has been developing digital-pixel focal plane array...
New CCD imagers for adaptive optics wavefront sensors
Summary
Summary
We report on two recently developed charge-coupled devices (CCDs) for adaptive optics wavefront sensing, both designed to provide exceptional sensitivity (low noise and high quantum efficiency) in high-frame-rate low-latency readout applications. The first imager, the CCID75, is a back-illuminated 16-port 160x160 pixel CCD that has been demonstrated to operate at...
Active hyperspectral imaging using a quantum cascade laser (QCL) array and digital-pixel focal plane array (DFPA) camera
Summary
Summary
We demonstrate active hyperspectral imaging using a quantum-cascade laser (QCL) array as the illumination source and a digital-pixel focal-plane-array (DFPA) camera as the receiver. The multi-wavelength QCL array used in this work comprises 15 individually addressable QCLs in which the beams from all lasers are spatially overlapped using wavelength beam...
Simultaneous dynamic pupil coding with on-chip coded aperture temporal imaging
Summary
Summary
We describe a new sensor that combines dynamic pupil coding with a digital readout integrated circuit (DROIC) capable of modulating a scene with a global or per-pixel time-varying, pseudo-random, and duo-binary signal (+1-1,0).