A unique, hyperspectral imaging plane "on-a-chip" developed for deployment as a High Performance Payload (HPP) on
a micro or small unmanned aerial vehicle is described. HPP employs nanophotonics technologies to create a focal plane
array with very high fill factor fabricated using standard integrated circuit techniques. The spectral response of each
pixel can be independently tuned and controlled over the entire spectral range of the camera. While the current HPP is
designed to operate in the visible, the underlying physical principles of the device are applicable and potentially
implementable from the UV through the long-wave infrared.
A standing wave spectrometer is turned into a wavelength tunable band-pass filter by the addition of a reflective coating.
It results in the standing wave filter (SWF), a miniaturized Fabry-Perot band-pass filter with a semi-transparent detector
that can be constructed into a pixel-tunable focal plane array, suitable for hyperspectral imaging applications. The
asymmetric Fabry-Perot cavity is formed between the reflective coating and a tunable mirror, originally part of the
spectrometer. The predicted performance of the SWF is optimized through modeling based on the matrix formalism used
in thin film optics and with FDTD simulations. The SWF concept is taken from an ideal device to a focal plane array
design that was fabricated with 40 micron pixels using semi-conductor processing technology. First-light spectra
measured from the 100 pixel Standing Wave Filter array agree with predictions and prove the concept.
Fabry-Perot filter arrays have been fabricated comprised of six million individual filters using standard semiconductor
processing techniques. The current 3000x2000 array consists of 5x5 sub-arrays in which each of the nine micron wide
Fabry-Perot filters in the sub-array has a different color response. The 5x5 sub-array is replicated to create a 600x400
matrix of 5x5 micro Fabry-Perot filter sub-arrays. This Fabry-Perot matrix has been integrated with a commercially
available panchromatic 6 Megapixel CCD focal plane array to create a 25 color hyperspectral camera with 600x400
imaging pixels. Near-UV, visible and NIR filter arrays have been fabricated. The semiconductor processing technique
permits filter arrays of general filter size, shape, configuration and distribution to be implemented with ease.
A new approach for microelectromechanical systems (MEMS) hydrophones is discussed, which yields miniature, low
power, and high performance hydrophones. The prototype devices use a laser interferometer with integrated low power
electronics built on conventional silicon on sapphire (SOS) complimentary metal oxide semiconductor (CMOS)
technology to optically detect pressure waves. Results show sensitivities of -143 dBV re 1 μPa, comparable to or better
than piezoelectric, capacitive condenser, or other optical approaches. The implication is to make very low cost
hydrophones while drastically reducing the power and computational requirements. This is viewed as a disruptive
technology for areas such as coastal defense and port security where cost, size and power consumption is key.
The function of a large number of MEMS and NEMS devices relies critically on the transduction method employed to convert the mechanical displacement into electrical signal. Optical transduction techniques have distinct advantages over more traditional capacitive and piezoelectric transduction methods. Optical interferometers can
provide a much higher sensitivity, about 3 orders of magnitude, but are hardly compatible with standard MEMS and microelectronics processing. In this paper, we present a scalable architecture based in silicon on sapphire (SOS) CMOS 1 for building an interferometric optical detection system. This new detection system is currently
being applied to the sense the motion of a resonating MEMS device, but can be used to detect the motion of any object to which the system is packaged. In the current hybrid approach the SOS CMOS device is packaged with both vertical cavity surface emitting lasers (VCSELs) and MEMS devices. The optical transparency of the sapphire substrate together with the ultra thin silicon PIN photodiodes available in this SOS process allows for the design of both a Michelson type and Fabry Perot type interferometer. The detectors, signal processing electronics and VCSEL drivers are built on the SOS CMOS for a complete system. We present experimental data demonstrating interferometric detection of a vibrating device.