We report on effective sulfur-based passivation treatments of type-II InAs/GaSb strained layer superlattice detectors (100% cut-off wavelength is 9.8 lm at 77 K). The electrical behavior of detectors passivated by electrochemical sulfur deposition (ECP) and thioacetamide (TAM) was evaluated for devices of various sizes. ECP passivated detectors with a perimeter-to-area ratio of 1600 cm 1 exhibi...

The University of Wisconsin-Madison has completed installation of a superconducting electron gun. Its concept was optimized to be the source for a CW free electron laser facility with multiple megahertz repetition rate end stations. This VHF superconducting configuration holds the promise of the highest performance for CW injectors. Initial commissioning efforts show that the cavity can achieve...

Low-temperature bonding methods of optoelectronic chips, such as laser diodes (LD) and photodiode (PD) chips, have been the focus of much interest to develop highly functional and compact optoelectronic devices, such as microsensors and communication modules. In this paper, room-temperature bonding of the optoelectronic chips with Au thin film to coined Au stud bumps with smooth surfaces (Ra: 1...

Interface states have been shown to have an appreciable effect on the performance of p-GaAs multilayer ~p-i-p-i. . . ! homojunction interfacial work function internal photoemission ~HIWIP! far-infrared detectors. In this article, a comparison of detector performance was made of p-GaAs HIWIP detectors with different interface state densities, with the emphasis on the detector’s dark current, noi...

A test socket chip for measuring dark currents of infrared (IR) detectors in a focal plane array (FPA) is presented in this paper. A calibration scheme adopted in this chip to cancel the leakage current due to OFF-state MOS switches tied to the measuring path is also demonstrated.

In this paper, we apply the perfect difference codes in wireless infrared systems considering the diffuse indoor optical wireless configuration. The bit error rate performance of the uplink wireless infrared system using Gaussian approximations is analyzed taking into account the effects of multiple-access interference, the ambient light noise, and the dark current. The proposed system also use...

The Long-Wavelength Spectrometer (LWS) onboard the Infrared Space Observatory (ISO) covers the 43-197m region with ten doped-Germanium photocon-ductors that are read out with integrating JF-4 ampli-ers. The behaviour of these detector/readout units during some 500 days of operations in space is described. There are no systematic variations of the sensitivity and of the dark current in observati...

The capacity and error exponent of the direct detection optical channel are considered. The channel input in a T-second interval is a waveform A(r), 0 5 t I T, which satisfies 0 I A(t) I A, and (l/r)],,%(t) dt I aA, 0 < IT 11. The channel output is a Poisson process with intensity parameter X(t) + he. ‘The quantities A and CIA represent the peak and average power, respectively, of the optical s...

In line with an ongoing programme to determine accurately x-ray attenuation coefficients, we have developed a method for the quantitative determination of the effect on experimental results of monochromator harmonic components in a synchrotron beam. The technique can be adapted to suit a wide variety of experiments, and is of particular interest because it determines the effect of the harmonic ...

The commissioning of the RPC-based muon detector in the BESIII experiment has been carried out. The RPC modules, front-end electronics, online and offline software of the muon system have been studied. The detector performances including efficiency, counting rate, noise ratio, spacial resolution, dark current, and muon charge ratio were obtained by cosmic ray data with and without magnetic fiel...