Design optimization and performance analysis of deformed optical readout focal plane array

Abstract

An optical readout focal plane array (FPA) usually has a bent cantilever due to the micro-machining techniques. This bent morphology has a strong negative impact on optical sensitivity, which is a key factor that affects the imaging performance. In this study, an optical readout FPA with a stiffener-supported pixel is presented in order to reduce the deformation. The theoretical analysis has been developed to optimize the structure. Based on this, an FPA with a stiffener-supported pixel is fabricated. It is demonstrated that the curvature radius and optical sensitivity can increase by 5 times and 5.74 times respectively with respect to that without a stiffener. Better thermal imaging has been achieved.

Optical sensitivity non-uniformity analysis and optimization of a tilt optical readout focal plane array

“…The processes begin with a <1 0 0> silicon wafer. (a) Two stiffeners that are used to attenuate the bend of reflector/absorber [14] beam. (g) The structure is released by back-side KOH wet etching and front-side XeF 2 dry etching.…”

“…Gao et al analyzed the relation between the optical sensitivity and undesired deformed parameters [13]. Fu et al presented a stiffener-supported structure to attenuate the deformation and increase the optical sensitivity [14].…”

Optical spatial filtering readout techniques for IR/THz imaging and their performance analysis

“…Infrared (IR) imaging is used extensively for military and civilian purposes. Terahertz (THz) imaging has also received a lot of attention recently because of its attractive features such as being harmless and capable of penetrating through fabric [1][2][3][4][5][6][7][8]. Compared to microbolometers, microcantilever focal plane arrays (MFPAs) offer a more sensitive and cheaper solution to far IR [9][10][11][12][13][14][15] and THz [1,16] imaging.…”