This report addresses the question of the choice of MEMS and detector element (facet and pixel respectively) sizes for the NGST near-infrared multi-object spectrograph NIRSpec. Using a specially modified spectroscopic exposure time calculator, we address both the ‘efficiency’ of observing single sources and the ‘speed’ of observing a field of sources with a space density typical for galaxies ne...

We have fabricated 63-element linear arrays of rnicromachined thermopile infrared detectors on silicon substrates. Each detector consists of a suspended silicon nitride membrane with 11 thermocouples of sputtered Bi-Te and Bi-Sb-Te films. At room temperature these detectors exhibit response times of 99 ms, zero frequency D* values of 1.4x109 cmHz’n/W and responsivity values of 1100 V/W when vie...

The photoacoustic (PA) effect, the generation of sound by the absorption of pulsed or modulated light, has been known since the famous experiments of Alexander Graham Bell in 1880. Scientific and practical applications of the photoacoustic technique have been considerably promoted by the invention of laser, which is an ideal light source for photoacoustics. Recently, photoacoustic detectors pla...

This paper represents algorithm for recognition of the coins of different denomination. The proposed system first uses a canny edge detection to generate an edge map, then uses CHT (Circular Hough transform) to recognize the coins and further find the radii of them. Based on the radius of the coin, the coins of different denomination are classified. The experimental result shows that the Hough ...

This paper reviews deposition, integration, and device fabrication of ferroelectric PbZrxTi1−xO3 (PZT) films for applications in microelectromechanical systems. As examples, a piezoelectric ultrasonic micromotor and pyroelectric infrared detector array are presented. A summary of the published data on the piezoelectric properties of PZT thin films is given. The figures of merit for various appl...

The problem of detecting sources of infrared radiation affects a large proportion of security alarm and distress signal systems. In a time of increasing property crime, it is highly important for passive infrared detectors (PIR) to be able to detect motion within the guarded area reliably and free of error. In the case of installation of passive infrared detectors (PIR) it is naturally importan...

Shortwave infrared (SWIR) photon detection has become an essential technology in the modern world. Sensitive SWIR detector arrays with high pixel density, low noise levels, and high signal-to-noise-ratios are highly desirable for a variety of applications including biophotonics, light detection and ranging, optical tomography, and astronomical imaging. As such many efforts in infrared detector ...

Despite the rapid advance of terahertz optoelectronics in the recent decade, the frequency region above 10 THz has yet been accessible for coherent detection. Whereas Katzenllenbogen et al. reported a frequency response of 6 THz from their photoconducting dipole antenna ~PDA!, the record was recently pushed to 7 THz with a much broader 3-dB bandwidth in a GaP-based free-space electro-optic samp...

Visibility estimators and their performance are presented for use with the Palomar Testbed Interferometer (PTI). One operational mode of PTI is single-baseline visibility measurement using pathlength modulation with synchronous readout by a NICMOS-3 infrared array. Visibility is estimated from the fringe quadratures, either incoherently, or using source phase referencing to provide a longer coh...