A tool that evaluates the magnitude of light intensity in relation to wavelength is an Optical Spectrum Analyzer. A sample schematic for usage in optical spectrum analyzers is displayed in the figure below. In many different applications, such as optical communications systems, optical spectrum analyzers are frequently used to assess wavelength-dependent performance parameters of electronic and optoelectronic devices that utilise lasers (such as transmitters). The properties of an unknown signal can be ascertained using a portable optical spectrum analyzer.

This is accomplished by measuring the amount of power present in each pass-band—also referred to as the "notch depth"—using analogue or digital filters that are tuned to particular frequencies.Its primary function is to analyse electromagnetic radiation with wavelengths ranging from microwaves to X-rays and everything in between. A tabletop Optical Spectrum Analyzer is a measurement-capable electronic device that can be used for a variety of tasks.

Read More @ http://cmiblogpost.weebly.com/article/the-role-of-optical-spectrum-analyzer-in-optical-signal-analysis-and-processing