This newly developed prototype Multispectral Polarized Scene Projector (MPSP), configured for the short wave
infrared (SWIR) regime, can be used for the test & evaluation (T&E) of spectro-polarimetric imaging sensors. The
MPSP system generates both static and video images (up to 200 Hz) with 512×512 spatial resolution with active spatial,
spectral, and polarization modulation with controlled bandwidth. It projects input SWIR radiant intensity scenes from
stored memory with user selectable wavelength (850-1650 nm) and bandwidth (12-100 nm), as well as polarization
states (six different states) controllable on a pixel by pixel basis. The system consists of one spectrally tunable liquid
crystal filter with variable bandpass, and multiple liquid crystal on silicon (LCoS) spatial light modulators (SLMs) for
intensity control and polarization modulation. In addition to the spectro-polarimetric sensor test, the instrument also
simulates polarized multispectral images of military scenes/targets for hardware-in-the loop (HIL) testing.
A newly fabricated Infrared Scene Projector (IRSP) configured for the Long Wave IR (LWIR) regime has
demonstrated simulated apparent temperatures exceeding 1500 oC, more than doubling the maximum
temperature capability of prior pixilated scene projector devices. Since the entire array surface is capable of
this high temperature output, the same device can be used to generate both the moderate temperature scene
background and an unlimited number of high temperature targets in the scene, without having to optically
combine a few discrete "hot spot" generators. This performance was enabled by advances in a new large pixel,
high voltage, 16-bit backplane Spatial Light Modulator (SLM) coupled with an intense spectral illumination
source, and special formulation liquid crystal (LC). The new LC formulation and SLM configuration also
achieves an effective usable frame rate of up to 200Hz capability. Performance characterization and resulting
data will be discussed in the paper.
We present ultrafast optical switching experiments on 3D photonic band gap crystals. Switching the Si inverse opal is
achieved by optically exciting free carriers by a two-photon process. We probe reflectivity in the frequency range of
second order Bragg diffraction where the photonic band gap is predicted. We observe a large frequency shift of up to
1.5% of all spectral features including the peak that corresponds to the photonic band gap. We also demonstrate large,
ultrafast shifts of stop bands of planar GaAs/AlAs photonic structures. We briefly discuss how our results can be used in
future switching and modulation applications.
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