Applications for short-wave infrared sensors continue to increase in commercial and military applications. Reducing pixel pitch decreases the size and cost expanding the ability to deploy sensors on smaller platforms including handheld and autonomous vehicles. Small pixel pitch cameras allow the user to shrink the lens thereby shrinking the total system size. Attollo Engineering will present the development of a VGA SWIR camera with 5 micron pixel pitch. Attollo will discuss designs of the components including detector, ROIC, and camera electronics. Attollo will show imagery and characteristics of the sensor.
Attollo has developed large area low capacitance InGaAs detectors to meet the needs of LiDAR systems following the roadmap of technology development at the near Infrared (NIR) wavelengths of 850/905/940 nm with the eventual transition to eye-safe wavelengths near 1550 nm. Attollo InGaAs offers large photodetector areas while still meeting the bandwidth limitations of the amplified detection system. Large area photodetectors enable a large system Field of View (FOV) with a simpler and larger diameter lens and also provide lower input-referred noise from optimized transimpedance amplifier systems. Attollo will present results on InGaAs detectors achieving capacitance densities 3x lower than state-of-the-art with 16 pF/mm2. Attollo will present LiDAR receiver modeling data utilizing these detectors and will quantify the advantages of low capacitance in LIDAR applications as it relates to system bandwidth and amplifier input referred noise performance of the system.
High-power, format flexible, 885 nm vertical-cavity surface-emitting laser (VCSEL) arrays have been developed for
solid-state pumping and illumination applications. In this approach, a common VCSEL size format was designed to
enable tiling into flexible formats and operating configurations. The fabrication of a common chip size on ceramic
submount enables low-cost volume manufacturing of high-power VCSEL arrays. This base VCSEL chip was designed
to be 5x3.33 mm2, and produced up to 50 Watts of peak continuous wave (CW) power. To scale to higher powers,
multiple chips can be tiled into a combination of series or parallel configurations tailored to the application driver
conditions. In actively cooled CW operation, the VCSEL array chips were packaged onto a single water channel cooler,
and we have demonstrated 0.5x1, 1x1, and 1x3 cm2 formats, producing 150, 250, and 500 Watts of peak power,
respectively, in under 130 A operating current. In QCW operation, the 1x3 cm2 VCSEL module, which contains 18
VCSEL array chips packaged on a single water cooler, produced over 1.3 kW of peak power. In passively cooled
packages, multiple chip configurations have been developed for illumination applications, producing over 300 Watts of
peak power in QCW operating conditions. These VCSEL chips use a substrate-removed structure to allow for efficient
thermal heatsinking to enable high-power operation. This scalable, format flexible VCSEL architecture can be applied
to wavelengths ranging from 800 to 1100 nm, and can be used to tailor emission spectral widths and build high-power
FLIR Electro Optical Components will present our latest developments in large InGaAs focal plane arrays, which are
used for low light level imaging in the short wavelength infrared (SWIR) regime. FLIR will present imaging from their
latest small pitch (15 μm) focal plane arrays in VGA and High Definition (HD) formats. FLIR will present
characterization of the FPA including dark current measurements as well as the use of correlated double sampling to
reduce read noise. FLIR will show imagery as well as FPA-level characterization data.
Practical, large-area, high-power diode pumps for one micron (Nd, Yb) as well as eye-safer wavelengths (Er, Tm, Ho)
are critical to the success of any high energy diode pumped solid state laser. Diode efficiency, brightness, availability
and cost will determine how realizable a fielded high energy diode pumped solid state laser will be. 2-D Vertical-Cavity
Surface-Emitting Laser (VCSEL) arrays are uniquely positioned to meet these requirements because of their unique
properties, such as low divergence circular output beams, reduced wavelength drift with temperature, scalability to large
2-D arrays through low-cost and high-volume semiconductor photolithographic processes, high reliability, no
catastrophic optical damage failure, and radiation and vacuum operation tolerance. Data will be presented on the status
of FLIR-EOC's VCSEL pump arrays. Analysis of the key aspects of electrical, thermal and mechanical design that are
critical to the design of a VCSEL pump array to achieve high power efficient array performance will be presented.
We describe the factors that go into the component choices for a short wavelength (SWIR) imager, which include the
SWIR sensor, the lens, and the illuminator. We have shown the factors for reducing dark current, and shown that we can
achieve well below 1.5 nA/cm2 for 15 μm devices at 7°C. We have mated our InGaAs detector arrays to 640x512
readout integrated integrated circuits (ROICs) to make focal plane arrays (FPAs). In addition, we have fabricated high
definition 1920x1080 FPAs for wide field of view imaging. The resulting FPAs are capable of imaging photon fluxes
with wavelengths between 1 and 1.6 microns at low light levels. The dark current associated with these FPAs is
extremely low, exhibiting a mean dark current density of 0.26 nA/cm2 at 0°C. FLIR has also developed a high definition,
1920x1080, 15 um pitch SWIR sensor. In addition, FLIR has developed laser arrays that provide flat illumination in
scenes that are normally light-starved. The illuminators have 40% wall-plug efficiency and provide low-speckle
illumination, provide artifact-free imagery versus conventional laser illuminators.
We describe the factors that go into the component choices for a short wavelength IR (SWIR) imager, which include the SWIR sensor, the lens, and the illuminator. We have shown the factors for reducing dark current, and shown that we can achieve well below 1.5 nA/cm2 for 15 μm devices at 7 °C. In addition, we have mated our InGaAs detector arrays to 640×512 readout integrated integrated circuits to make focal plane arrays (FPAs). The resulting FPAs are capable of imaging photon fluxes with wavelengths between 1 and 1.6 μm at low light levels. The dark current associated with these FPAs is extremely low, exhibiting a mean dark current density of 0.26 nA/cm2 at 0 °C. Noise due to the readout can be reduced from 95 to 57 electrons by using off-chip correlated double sampling. In addition, Aerius has developed laser arrays that provide flat illumination in scenes that are normally light-starved. The illuminators have 40% wall-plug efficiency and provide low-speckle illumination, and provide artifact-free imagery versus conventional laser illuminators.
Aerius Photonics will present their latest developments in large InGaAs focal plane arrays, which are used for low light
level imaging in the short wavelength infrared (SWIR) regime. Aerius will present imaging in both 1280x1024 and
640x512 formats. Aerius will present characterization of the FPA including dark current measurements. Aerius will
also show the results of development of SWIR FPAs for high temperaures, including imagery and dark current data.
Finally, Aerius will show results of using the SWIR camera with Aerius' SWIR illuminators using VCSEL technology.
Short wavelength IR imaging using InGaAs-based FPAs is shown. Aerius demonstrates low dark current in InGaAs
detector arrays with 15 μm pixel pitch. The same material is mated with a 640x 512 CTIA-based readout integrated
circuit. The resulting FPA is capable of imaging photon fluxes with wavelengths between 1 and 1.6 microns at low light
levels. The mean dark current density on the FPAs is extremely low at 0.64 nA/cm2 at 10°C. Noise due to the readout
can be reduced from 95 to 57 electrons by using off-chip correlated double sampling (CDS). In addition, Aerius has
developed laser arrays that provide flat illumination in scenes that are normally light-starved. The illuminators have
40% wall-plug efficiency and provide speckle-free illumination, provide artifact-free imagery versus conventional laser
Recent advances in Vertical-cavity Surface-emitting Laser (VCSEL) efficiency and packaging have opened up
alternative applications for VCSELs that leverage their inherent advantages over light emitting diodes and edge-emitting
lasers (EELs), such as low-divergence symmetric emission, wavelength stability, and inherent 2-D array fabrication.
Improvements in reproducible highly efficient VCSELs have allowed VCSELs to be considered for high power and high
brightness applications. In this talk, Aerius will discuss recent advances with Aerius' VCSELs and application of these
VCSELs to miniature optical sensors such as rangefinders and illuminators.
Aerius Photonics has developed large InGaAs arrays (1K x 1K and greater) with low dark currents for use
in night vision applications in the SWIR regime. Aerius will present results of experiments to reduce the
dark current density of their InGaAs detector arrays. By varying device designs and passivations, Aerius
has achieved a dark current density below 1.0 nA/cm2 at 280K on small-pixel, detector arrays. Data is
shown for both test structures and focal plane arrays. In addition, data from cryogenically cooled InGaAs
arrays will be shown for astronomy applications.
Polarization is increasingly being considered as a method of discrimination in passive sensing applications. In this paper
the degree of polarization of the thermal emission from the emitter arrays of two new Santa Barbara Infrared (SBIR)
micro-bolometer resistor array scene projectors was characterized at ambient temperature and at 77 K. The emitter
arrays characterized were from the Large Format Resistive Array (LFRA) and the Optimized Arrays for Space-Background Infrared Simulation (OASIS) scene projectors. This paper reports the results of this testing.
The next generation of low-cost smart munitions will be capable of autonomously detecting and identifying targets aided partly by the ability to image targets with compact and robust scanning rangefinder and LADAR capabilities. These imaging systems will utilize arrays of high performance, low-cost semiconductor diode lasers capable of achieving high peak powers in pulses ranging from 5 to 25 nanoseconds in duration. Aerius Photonics is developing high-power Vertical-Cavity Surface-Emitting Lasers (VCSELs) to meet the needs of these smart munitions applications. The authors will report the results of Aerius' development program in which peak pulsed powers exceeding 60 Watts were demonstrated from single VCSEL emitters. These compact packaged emitters achieved pulse energies in excess of 1.5 micro-joules with multi kilo-hertz pulse repetition frequencies. The progress of the ongoing effort toward extending this performance to arrays of VCSEL emitters and toward further improving laser slope efficiency will be reported.
Vertical cavity surface emitting lasers (VCSELs) operating near 1310 or 1550 nm have been the subject of intensive research by multiple groups for several years. In the past year at Gore, we have demonstrated the first 1300 nm VCSELs which operate with useful power, high modulation rate, and low voltage over the commercial temperature range of 0 - 70 degree(s)C. These results have been achieved using a new structure in which an 850 nm VCSEL optical pump is integrated with the 1300 nm VCSEL. Electrical drive is applied to the 850 nm pump, and 1300 nm light is emitted from the integrated structure. This approach has resulted in over a milliwatt of single transverse mode power at room temperature, and several hundred microwatts of single transverse mode power at 70 degree(s)C. In addition, these devices demonstrate multi-gigabit modulation and excellent coupling efficiency to single-mode fiber.