The value proposition for Short-Wave Infrared (SWIR) includes capabilities beyond standard passive, low-noise imaging. Sensors Unlimited Inc. (SUI), a Raytheon Technologies Company, has expanded its multi-mode tracking (MMT) portfolio with the development of two new solutions, each of which offers laser range finding (LRF) capability. The SWIR Pocket Scope-MMT (SPS-MMT) sets the gold standard for asynchronous laser pulse detection (ALPD) and low-noise passive imaging, internally dubbed MMT, in a SWIR hand-held solution. SUI’s expanded portfolio now includes a variant of that product with an embedded LRF so that the warfighter can simultaneously, image, track and decode any laser designators, and determine the distance to any targets in the same scene of interest. Additionally, SUI has developed an HD version of that capability set. Performance results of each solution will be described herein.
Sensors Unlimited Inc. (SUI), a Raytheon Company, continues to expand its sensor portfolio through the development of time-of-flight (TOF) capable technologies. The utility of SWIR for active TOF solutions is of particular interest due to its inherent eye safety characteristic. SUI is developing TOF technologies both at the detector and readout integrated circuit (ROIC) layers of the focal plane array (FPA). In this work, SUI will offer updates to the internal development efforts comprising both areas as it pertains to the time-of-flight technologies.
In this work, SUI presents an update on PIN Photodiode Array (PDA) developments and the advancements in Avalanche Photodetectors (APD) Array development. SUI continue to push the PIN based SWIR photodetector performance by reducing the dark current, increasing the quantum efficiency in broad spectral wavelength range from 400nm to 1700nm and extending the wavelength to 2.6μm. We will also present APD technology advancements specifically related to low temperature performance from room temperature to 260K and Geiger Mode operation. In addition, we will discuss the requirements of Readout Integrated Circuits (ROIC) for APD based sensor development for synchronous and asynchronous pulse detection and active and passive quenching mechanisms. We will also discuss 2-D and 3-D TCAD simulation results at low temperature and compare them with measured performance results. Finally, recent results related to the advanced development of Geiger Mode Avalanche Photodetectors (GMAPD) and the results using passive and active quenching circuits are presented.
Improved situational awareness using SWIR is of upmost importance to many of SUI's, a Collins Aerospace company, customers. SUI’s proprietary Asynchronous Laser Pulse Detection (aka MMT, Multi-Mode Tracking) methodology facilitates the detection, tracking, and decode of NIR-SWIR lasers at the pixel level at all ambient lighting conditions without the compromising imaging performance. This paper describes advancing this technology for improved hostile detection. The main challenge of hostile detection using infrared imaging technologies is the requirement for fast frame rates as the signal lifetime is short for both retroreflection and muzzle flash detection. In this work, SUI demonstrates how its MMT technology can be leveraged for low SWaP hostile detection applications.
Recent short-wave infrared (SWIR) sensors have demonstrated in-pixel multimode capabilities. One of the additional modes is range finding. High resolution range finding is increasingly becoming vital functionality in high precision targeting and imaging systems. Highly precise and accurate range-to-target information is essential for many modern commercial and military applications. With the recent advances in LiDAR (Light Detection and Ranging) technology, range measurement accuracies as low as a centimeter at kilometer ranges. Sensors Unlimited Inc. (SUI), a Raytheon Technologies (RTX) Company, has been developing these multimode sensors using traditional PIN-based InGaAs detector technology. However, the capability of these sensors has been extended through the introduction of Avalanche Photodetector (APD) InGaAs sensors. This APD technology has been developed onshore to better serve the onshore community requiring simultaneous laser tracking, ranging, and imaging applications. In this work, SUI offers an update on previously presented, PDA-specific development, most specifically related to the advancement of Geiger Mode Avalanche Photodetectors (GMAPD). SUI’s APD technology is in direct response to the challenging SWaP and NEI performance requirements of active imaging and tracking applications. This update includes 2D and 3D TCAD simulation results with a comparison with measured performance results. Finally, initial results related to the advanced development of Geiger Mode Avalanche Photodetectors (GMAPD) themselves as well as supporting electronics is given. The revitalization of SUI’s APD development is a direct response to the challenging SWaP and longer-range with higher accuracy performance requirements of active imaging applications. SUI’s most recent APD design improvements facilitates greater signal to noise ratio at the pixel, which subsequently enables a supporting ROIC pixel design with improved performance.
KEYWORDS: Aerospace engineering, Photodetectors, Diffusion, Modulation transfer functions, Avalanche photodetectors, Readout integrated circuits, Personal digital assistants, Metals, Short wave infrared radiation, Scanning electron microscopy
Increasing shortwave infrared (SWIR) sensor performance requirements have pushed traditional HOT detector technologies to their limits. Collins Aerospace Princeton, a Raytheon Technologies (RTX) Company, has answered this call by looking beyond dark current reduction, and leveraging its onshore foundry capabilities to develop unprecedented, high performance photodetector array (PDA) technologies to better serve both passive and active imaging applications. In this work, Collins Aerospace Princeton offers an update on several previously presented, PDA-specific development fronts as well as offering introductions into other novel efforts. In addition to presenting current state-ofthe-art (SOA) InGaAs dark current performance, results related to mesa-structure PDAs for modulation transfer function (MTF) improvement and hybridization capacitance reduction for active imaging noise equivalent irradiance (NEI) improvement are offered. Additionally, focal plane array (FPA) interconnection improvement techniques and results for yield improvement and cost reduction are presented. Finally, results related to the three most advanced and nascent development tracks, avalanche photodiode (APD), PDA metallization and single side bumped FPA, are introduced. Collins Aerospace Princeton’s APD technology is in direct response to the challenging size, weight, and power (SWaP) and NEI performance requirements of active imaging applications. Similarly, Collins Aerospace Princeton’s PDA metallization technology, inspired by silicon-based brethren, facilitates greater integration capability on the PDA itself, which subsequently allows for greater functionality and performance at every pixel location. The most recently developed single side bumped FPA will dramatically improve operability with reduced cost. Overall, these PDA-specific developments represent the most innovative SWIR technology portfolio known to date.
KEYWORDS: Sensors, Short wave infrared radiation, Personal digital assistants, Photodiodes, Modulation transfer functions, Sensor technology, Detector arrays, Capacitance
Sensors Unlimited Inc. (SUI), a Raytheon Technologies Company, has long been the vanguard of low-noise InGaAs/InP PiN back-side illuminated (BSI) planar-type photodiode technology. In addition to focusing on dark current reduction efforts, SUI has also initiated other photodiode detector array (PDA) improvement efforts to better serve its broad portfolio of sensor technology. In previous years, SUI has presented results related to mesa-structure PDAs for modulation transfer function (MTF) improvement and hybridization capacitance reduction for NEI improvement. An update to these technologies is offered. Additionally, SUI has more recently engaged in more advanced PDA development to better satisfy active imaging applications. Results of these efforts are also presented.
We have designed and developed a new family of photodetectors and arrays with Internal Discrete
Amplification (IDA) mechanism for the realization of very high gain and low excess noise factor in the
visible and near infrared spectral regions. These devices surpass many limitations of the Single Photon
Avalanche Photodetectors such as ultra low excess noise factor, very high gain, lower reset time (< 200 ns).
These devices are very simple to operate in the non-gated mode under a constant dc bias voltage. Because
of its unique characteristics of self-quenching and self-recovery, no external quenching circuit is needed.
This unique feature of self quenching and self-recovery makes it simple to less complex readout integrated
circuit to realize large format detector arrays.
In this paper, we present the discrete amplification design approach used for the development of self reset,
high gain photodetector arrays in the near infrared wavelength region. The demonstrated device
performance far exceeds any available solid state Photodetectors in the near infrared wavelength range.
These devices are ideal for researchers in the field of spectroscopy, industrial and scientific
instrumentation, Ladar, quantum cryptography, night vision and other military, defense and aerospace
applications.
We present the design and development of a negative feedback devices using the internal discrete amplifier
approach used for the development of a single photon avalanche photodetector in the near infrared
wavelength region. This new family of photodetectors with negative feedback, requiring no quenching
mechanism using Internal Discrete Amplification (IDA) mechanism for the realization of very high gain
and low excess noise factor in the visible and near infrared spectral regions, operates in the non-gated mode
under a constant bias voltage. The demonstrated device performance far exceeds any available solid state
Photodetectors in the near infrared wavelength range. The measured devices have Gain > 2×105, Excess
noise factor < 1.05, Rise time < 350ps, Fall time < 500ps, Dark current < 2×106 cps at room temperature,
and Operating Voltage < 60V. These devices are ideal for researchers in the field of Ladar/Lidar, free space
optical communication, 3D imaging, industrial and scientific instrumentation, night vision, quantum
cryptography, and other military, defence and aerospace applications.
We present the discrete amplification approach used for development of a very high gain and low excess noise factor in
the near infrared wavelength region. The devices have the following performance characteristics: gain > 2X105, excess
noise factor < 1.05, rise time < 350ps, fall time < 500ps and operating voltage < 60V. In the photon counting mode, the
devices can be operated in the non-gated mode under a constant DC bias and do not require any external quenching
circuit. These devices are ideal for researchers in the fields of deep space optical communication, spectroscopy,
industrial and scientific instrumentation, Ladar/Lidar, quantum cryptography, night vision and other military, defense
and aerospace applications.
KEYWORDS: Photodetectors, Near infrared, Sensors, Avalanche photodetectors, Photon counting, Solid state photomultipliers, Optical amplifiers, Analog electronics, Single photon, Measurement devices
A new family of photodetectors with a Discrete Amplification (DA) mechanism allows the realization of very high gain
and low excess noise factor in the visible and near infrared spectral regions and offers an alternative to conventional
photomultiplier tubes and Geiger mode avalanche photodetectors. These photodetectors can operate in linear detection
mode with gain-bandwidth product in excess of 4X1014 and in photon counting mode with count rates up to 108
counts/sec. Potential benefits of this technology over conventional avalanche photodetectors include ultra low excess
noise factor, very high gain, and lower reset time (<< 1 μs). In the photon counting mode, the devices can be operated in
the non-gated mode under a constant dc bias. Because of its unique characteristics of self-quenching and self-recovery,
no external quenching circuit is needed.
We present the discrete amplification design approach used for the development of a solid state photomultiplier in the
near infrared wavelength region. The demonstrated device performance far exceeds any available solid state
photodetectors in the near infrared wavelength range. The measured devices have the following performance
characteristics: gain > 2X105, excess noise factor < 1.05, rise time < 350ps, fall time < 500ps, dark current < 2X106 cps,
operating voltage < 60V. These devices are ideal for researchers in the field of deep space optical communication,
spectroscopy, industrial and scientific instrumentation, Ladar/Lidar, quantum cryptography, night vision and other
military, defence and aerospace applications.
KEYWORDS: Photodetectors, Signal detection, Sensors, Molecules, Analog electronics, Amplifiers, Photon counting, Avalanche photodetectors, Near field optics, Optical instrument design
The detection and identification of single molecules represent one of the ultimate goals of analytical chemistry. We have
designed, developed and tested a new family of photodetectors with Internal Discrete Amplification (IDA) mechanism.
These photodetectors can operate in linear (analog) detection mode with gain-bandwidth product up to 5.1014 and one- or
few-photon sensitivity, as well as in the photon counting mode with count rates up to 108 cps. Their key performance
characteristics exceed those of photomultiplier tube (PMT) and avalanche photodiode (APD) devices. The measured
parameters of the detectors are: gain > 105, excess noise factor as low as 1.02, maximum count rate > 108 counts/s, and rise/fall time < 300 ps. The new family of the photo detectors may become an ideal solution for the problems of
ultrasensitive and single-molecule detection by fluorescence spectroscopy and other optical methods.
We have designed and developed a new family of photodetectors with Internal Discrete Amplification (IDA) mechanism
They operate as solid state photomultiplier devices at room temperature and may be used in numerous applications
where high bandwidth of the detector is necessary in combination with maximum sensitivity and low excess noise. The
photodetectors can operate in linear detection mode with gain-bandwidth product up to 5 times 1014 as well as in photon
counting mode with count rates up to 108 counts/sec. The key performance characteristics exceed those of
Photomultiplier Tube (PMT) and Avalanche Photodiode (APD) devices. The detectors have gain > 105, excess noise
factor as low as 1.03, photoresponse rise/fall time < 300 ps, and timing resolution (jitter) < 200 ps. The combination of
low excess noise at high gain and wide bandwidth, as well as scalability to large active areas, presents the main
advantages of this technology over conventional photodetector solutions. Ultra low excess noise is one of the main
features of the internal Discrete Amplification Detector (DAD), and in this paper its nature has been investigated more
comprehensively. We investigated the behavior of the noise-factor and afterpulsing, and conclude that both have the
same physical nature. Optical cross-talk between channels is shown to be responsible for the afterpulsing phenomenon,
and, in turn, is the main source of excess noise. Thus, the noise characteristics of an DAD device and its timing
resolution may be significantly improved as they are limited not by the discrete amplifier channel properties itself, but by
the cross-talk, which strongly depends on the device design.
Recent advances in bio-optical methods for Medical Diagnostics, Optical Biopsy and Non-Invasive Imaging have the
potential to prolong and improve the quality of life while significantly reducing medical costs for the diagnosis and
tracking of diseases. Advances in the Genomics and pharmaceutical discovery using micro-array technology and High
Throughput Screening permit to study thousands of compounds in short periods of time. This paper presents a new Si-based
photonic sensors and sensor arrays with internal discrete amplification that offers the necessary qualities thus
allowing development of a new generation of high gain, ultra low noise, universal analog and counting photodetectors
for bio-optical sensing applications. The new photodetectors can operate in the linear detection mode with a gain-bandwidth
product of up to 1015/sec and in the photon counting mode with count rates of up to 109 counts/sec. Detectors
based on this amplification mechanism could have performance parameters superior to those of conventional avalanche
photodiodes and photomultiplier tubes. For tested silicon photodetector prototypes, measured excess noise factor is as
low as 1.02 at gains greater than 100,000.
We demonstrate the feasibility of applying the emerging technology of internal discrete amplification to create an efficient, ultra low noise, universal analog and counting photodetector for LIDAR remote sensing. Photodetectors with internal discrete amplification can operate in the linear detection mode with a gain-bandwidth product of up to 1015 and in the photon counting mode with count rates of up to 109 counts/sec. Detectors based on this mechanism could have performance parameters superior to those of conventional avalanche photodiodes and photomultiplier tubes. For silicon photodetector prototypes, measured excess noise factor is as low as 1.02 at gains greater than 100,000. This gives the photodetectors and, consequently, the LIDAR systems new capabilities that could lead to important advances in LIDAR remote sensing.
We have designed and developed a new family of photodetectors with Internal Discrete Amplification (IDA) mechanism. These photodetectors can operate in linear (analog) detection mode with gain-bandwidth product up to 5.1014 and few-photon sensitivity as well as in the photon counting mode with count rates up to 108 cps. Some of their key performance characteristics exceed those of photomultiplier tube (PMT) and avalanche photodiode (APD) devices. The measured parameters of the detectors are gain > 105, excess noise factor as low as 1.02, maximum count rate > 108 counts/s, and rise/fall time < 300 ps.
Performance of a SWIR FPA targeting LANDSAT S/N levels in the near room temperature (> 220 K) is presented. The FPA consists of a 96 X 25 element InGaAs array with 48 (mu) X 48 (mu) photo-voltaic pixels bump-bonded to a Si multiplexer. Cutoff wavelength of an array is tailored from 1.68 (mu) to 2.4 (mu) . The longer cutoff is required for Band 7. The multiplexer design incorporates a CMOS CCD process and is a 96 channel X 25 TDI scanning array with pixel pitch of 48 (mu) cross track by 96 (mu) intrack. Each unit cell uses a Capacitive Trans-Impedance Amplifier) with Correlated Double Sampling. Other notable chip features include electrically selectable TDI modes (0, 1, 8, 16, and 25), forward and reverse scan, and 1 X 1 and 2 X 2 aggregation modes. Timing and biases are self generated by the multiplexer.
A design is presented for 512-element CTIA multiplexer developed for readout of an array of 1024-element InGaAs detectors for operation with a bias voltage in the range of +/- 10 mV. This multiplexer can be operated with a left-to-right or right-to-left scan, a non- destructive sequential readout with line-by-line selectable detector reset, and with or without input-MOSFET-threshold uniformity correction. The optical integration time in the range from 20 ms to 10 min is selectable in multiples of 20 to 40 ms line times. The multiplexer cell architecture includes a differential CTIA with open-loop gain of about 5000, a CDS circuit, and two unity-grain buffer amplifiers.
We have measured the effects of radiation on various long wavelength diode devices using InGaAs technology. The various components were exposed to radiation of continuous electron and gamma beams at the Lehigh University Van de Graaff Radiation Facility and proton beams at the Brookhaven Tandem Facility.
This paper describes a unique and high-performance 1024-element linear InxGa1-xAs/InAsyP1-y detector array for environmental sensing applications in the 1 micrometers to 2.6 micrometers spectral range. The detector array was fabricated using hydride vapor phase epitaxy grown material. The size of each pixel of the detector array is 13 X 500 micrometers 2 with 25 micrometers pitch. Improvements in dark current and quantum efficiency were realized by optimization of crystal growth, thermal annealing, and diffusion techniques. Transmission electron microscopy analysis of the fabricated structure was used to find the effect of thermal annealing on the dislocation density and the leakage current. The measured results of the 1024-element detector array sliver is presented.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.