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|Author(s):||Howard W. Yoon; Matt Dopkiss; George P. Eppeldauer;|
|Title:||Performance Comparisons of InGaAs, Extended InGaAs and Short-Wave HgCdTe Detectors Between 1 [mu]m and 2.5 [mu]m|
|Abstract:||In this study, three different detectors, regular InGaAs, short-wave infrared extended-InGaAs (exInGaAs) with the bandgap wavelength at 2.6 mm and short-wave HgCdTe (swMCT) with the bandgap wavelength at 2.8 mm are studied. The detectors have active areas of 3 mm or 1 mm diameter with all the detectors capable of being cooled from room temperatures to -85 oC with 4-stage thermo-electric coolers. Two of the detectors have field-of-view limiting, cold shrouds attached. From room temperatures to their coldest operating temperatures, the detectors are compared for their temperature-dependent shunt resistances, absolute spectral power responsivities, and noise performances at the output of the photocurrent meter. The photodiode current measuring circuit is analyzed to determine the effect of the shunt resistance for the output offset voltage, the noise and drift amplification, the uncertainty of the current-to-voltage conversion, and the linear operation. The temperature dependences of the shunt resistances are described by Arrhenius plots, and the spectral power responsivities are determined against a pyroelectric detector standard with constant responsivity versus wavelength. We determine that the shunt resistances of regular InGaAs photodiodes can increase to 5 GW when cooled to -20 oC demonstrating Si-like performance. The shunt resistances of the 1 mm diameter extended InGaAs and short-wave MCT photodiodes were both measured to be about 11 MW at diode temperatures of -70 oC. Further increase in the shunt resistances would be possible with decreasing diode temperatures. The noise voltage at the output of the photocurrent-to-voltage converter is measured for the respective detectors to determine the noise-equiv|
|Conference:||SPIE Optics and Photonics Conference|
|Dates:||August 13-16, 2006|
|Keywords:||extended InGaAs,infrared detectors,InGaAs,MCT,NEP,noise,responsitivy,shunt resistance,temperature dependence|