Image intensified photodiode array

An intensified photodiode array (IPDA) detector for onedimensional spatial imaging in the EUV is shown in Figure 2. This type of detector was originally described by Riegler and Moore (14) It consists of a microchannel plate whose output is optically coupled to a self scanning photodiode array. An incident photon produces a photoelectron which is subsequently amplified by the MCP. The exiting electrons are proximity... 

The performance characteristics of four optoelectronic image detectors (OIDs) are discussed. The detectors discussed are the silicon intensified target vidicon (SIT), the intensified SIT, the intensified silicon photodiode array detector (ISPD), and the self-scanned photodiode array detector. The main objective of the paper is to provide research workers interested in applying OIDs to a particular application with comparative performance information so that the best detector for a particular application may be selected. 

This paper will concentrate on the unique requirements of aeronomic spectroscopy and on the application of image devices to these measurements. Spectrometer 1, Table I, was developed for rocket experiments intended to measure the NIR absorption spectra of 1 0 and 02 molecules in the middle atmosphere. A photodiode array was used as the spectrometric sensor. With this spectrometer we were able to measure the NIR solar radiation spectrum with an altitude resolution better than 2 km. Spectrometer 2, Table I, was basically of the same design as spectrometer 1, except that an image intensifier was optically coupled to the diode array to permit low light-level measurements. The resolution of this spectrometer was adequate for measurements of rotational profiles of the A-band absorption spectra of 02 molecules. We were able to measure the rotational temperature of oxygen molecules, in the stratosphere and the lower mesosphere with an accuracy of + 1.5°, and a spatial resolution better than 2 km. These experiments provided the basis for study of the dynamic processes of atmospheric molecules. Spectrometer 3,... 

Figures, (a) A schematic diagram of the rocket-borne spectrometer designedfor measuring the rotational profile of the A-band absorption spectrum of O, molecules. Key II, image intensifier IS, photodiode array CG, clock generator CC, clock controller and PD, photodiode. (Reproduced with permission from Ref. II. Copyright 1983, American Geophysical Union.)...

Figure C3.1.5. Schematic diagram of an intensifier-gated optical multichannel analyser (OMA) detector. The detector consists of a microchannel plate (MCP) image intensifier followed by a 1024-channel Reticon photodiode array. Light dispersed across the semitransparent photocathode ejects photoelectrons. These are accelerated toward the entrance of the microchannels by the gate pulse. The photoelectrons collide with the channel walls to produce secondary electrons, which are accelerated in turn by the MCP bias voltage to produce further collisions and electron multiplication. Electrons leaving the microchannels are further accelerated by the phosphor bias voltage.

Many newer Raman instruments have replaced the single-wavelength output monochromator with a spectrograph and an array detector. The photodiode array was the first array detector to be used. It allows the simultaneous collection of entire Raman spectra. Photodiode arrays are typically used in conjunction with an image intensifier to amplify the weak Raman signal. 

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