An angle-resolved, true 3D laser sensor system for autonomous vehicles and driverless cars has been developed. This paper will describe the principle and architecture of autonomous vehicle laser sensors with the potential for nanowatt, single digit angular resolution at low false alarm rates, and wide angular coverage demonstrated so far for lasers in the 450-1550 nm spectral band, but with the capability for near-mid, mid-IR and longwave IR, as well as active/passive operation. The true 3D sensor determines in real-time, the range, angle and intensity of every resolved feature in the 3D point-cloud unlike conventional lidar sensor systems that can determine only the range of objects accurately. The underlying technology is based on ultra high gain, low excess noise, linear-mode APD detectors, angle resolving optics and open architecture software and interfaces all in a small form-factor. It is also based on a breakthrough tactical laser sensing technology, which have successfully undergone lab and outdoor testing and has demonstrated broadband, widefield- of-view operation with high sensitivity and low false alarm rates. The sensor architecture, design concepts, measured performance and projections will be presented, as well as trade-off characteristics among performance specifications, such as sensitivity, false alarm rates and detection probability.
This paper reports the demonstration of single photon counting receivers with pulse detection efficiency as high as 68%
for 2 photons and single photon counting probabilities as high as 44% at 1550-nm, 1 MHz rate and room temperature
and with linear-mode (below the breakdown voltage), high speed response in the 450-1700 nm spectral band. The
developed single photon counting receiver is based on Epitaxial Technologies' ultra high gain (>300000), low excess
noise, linear-mode APDs, which have been fabricated in dimensions ranging from 25 to 200-μm and array formats up to 32 x 32.
We report high gain, high sensitivity 1064-1550 nm avalanche photodiodes (APDs) that are capable of single photon counting in the linear mode below the breakdown voltage and at room temperature. Epitaxial Technologies has developed AlInAs/GaInAs APDs with multiplication gains as high as 347,000, sensitivities of -69 to -77 dBm and photon detection efficiencies as high as 27%. The single photon counting APDs are free of afterpulse artifacts even for pulse widths in the nanosecond range. They can detect single photons at up to 139 MHz and have the capability for gigahertz repetition rate. Based on innovative and proprietary APD production technologies, the APDs have excess noise factors as low as 2 with the high gain. To our knowledge, these are the highest multiplication gains simultaneous with low excess noise factors and high sensitivities reported so far for long wavelength APDs.
Epitaxial Technologies has developed a single photon counting photoreceiver that can operate in the linear mode to
avoid the drawbacks of Geiger mode detectors. The Company's linear single photon counting photoreceiver array
technology is based on cascading optical amplifiers on-chip with APDs to enable single photon capability below the
APD breakdown voltage through ultra-low noise gain and preamplification. We have already demonstrated components
for this photoreceiver that when implemented will have single photon sensitivities for subnanosecond pulses with high
photon counting efficiency and without afterpulsing at 1064 and
This paper describes the design, growth and fabrication characterization of novel multi-wavelength QWIP wafers based on InP material systems. We designed, grew, fabricated and characterized AlGaInAs/GaInAs QWIPs suitable for operation at 3-5 μm, and 8-12 μm spectral range. We fabricated mid-wave IR 320 x 250 focal plane arrays, hybridized them with Si -readout circuits and performed radiometric and imaging tests. Excellent imaging results of the mid-wave IR focal plane arrays with an operability of 88% and mean NEDT of 0.09K have been achieved. To our knowledge, this
is the first imaging with InP based QWIPs focal plane array.