Ocean Optics NIR - Manual (Page 33)

Appendix C
NIR256-2.5µm Sensitivity
When configuring a system for operation out to 2.5µ m it is important that you consider the following
details:
• Short Integration Times: For the detector to be sensitive out to 2.5µm, the detector’s band gap
energy must be small. Unfortunately, this raises the absolute level of the detectors dark signal. A
typical dark signal at 34ms is shown below. While the detector functions at integration times
greater than 50ms, this seems to be the realistic limit.
• Fiber Selection: For maximum signal intensity, alternative fiber materials should be used for
wavelengths greater than 2.2µ m.
The figure below shows a dark signal at 24ms integration time. Full Scale is 65,535 counts. The spectra
shows the presence of a defective pixel.
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