Resolution, silicon photodiode array

We employ method B to study effects of this type. In this mode, our apparatus yields relative high-resolution fluorescence spectra at different time windows after excitation of the sample by the 355 nm pulse. The spectra are acquired by the upconversion method. The upconverted fluorescence spectrum is recorded simultaneously at all monitored wavelengths by an optical multichannel analyzer. It is constructed from a poly-chromator (HR320 Instruments SA) and an intensified silicon photodiode array detector (Princeton Applied Research Model 1412). The detector is interfaced to our Cromemco computer. 

For detection in the UV-visible region, photomultipliers or other photoelectric devices are used. Some instruments may use a multi-channel diode array detector. An array of typically 300 silicon photodiodes detects all the wavelengths simultaneously with a resolution of about 1 nm. This provides a great saving in time and an improved signal/noise ratio. 

Semiconductor silicon diodes, called photodiodes, with special conductance properties are generally used in diode array spectrophotometers. Photodiodes are very useful because scan times of the order of a few milliseconds and thus many scans may be obtained in a very short time. In addition, the data obtained, being digital, can be further processed to generate spectra with a very high degree of resolution and accuracy. 

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