Recent advancements in gallium antimonide light emitting diode (LED) arrays have opened the way for the
development of LED-based infrared scene projectors. Infrared LED array technology offers the opportunity for
high frame rates, broad dynamic range, and high apparent temperatures. Since LEDs are narrow-band devices,
relative to blackbody emitters, performance of an LED-based infrared scene projector is highly dependent on how
effective and apparent temperatures are calculated in a detector system being tested. Because of this dependence,
methods used to compute effective and apparent temperatures are reviewed and applied to published radiometric
data from a gallium antimonide LED array. These calculations are used to investigate the effects of detector
spectral response, emitter array fill factor, emitter radiant flux distribution, and detector aperture size on the
apparent temperature of the LED array. This investigation leads into an analysis of the potential performance
advantages and technical challenges of an LED-based infrared scene projector system.
The emergence of spectrally multimode smart missiles requires hardware-in-the-loop (HWIL) facilities to simulate
multiple spectral signatures simultaneously. While traditional diode-pumped solid-state (DPSS) sources provide a great
basic testing source for smart missiles, they typically are bulky and provide substantially more power peak power than
what is required for laboratory simulation, have fixed pulse widths, and require some external means to attenuate the
output power. HWIL facilities require systems capable of high speed variability of the angular divergence and optical
intensity over several orders of magnitude, which is not typically provided by basic DPSS systems. In order to meet the
needs of HWIL facilities, we present a low-cost semi-active laser (SAL) simulator source using laser diode sources that
emits laser light at the critical wavelengths of 1064 nm and 1550 nm, along with light in the visible for alignment, from a
single fiber aperture. Fiber delivery of the multi-spectral output can provide several advantages depending on the testing
setup. The SAL simulator source presented is capable of providing attenuation of greater than 70 dB with a response
time of a few milliseconds and provides a means to change the angular divergence over an entire dynamic range of 0.02-
6º in less than 400 ms. Further, the SAL simulator is pulse width and pulse repetition rate agile making it capable of
producing both current and any future coding format necessary.
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.