Advantest Q8347
Optical Spectrum Analyzer uses a Michelson interferometer. The larger mechanical configuration of the interferometer allows max. resolutions of 1 pm or 1 GHz in the frequency mode. This resolution as well as a measurement accuracy of 0.001 nm for interferometers of this size cannot be attained with monochromators. At 1550 nm the resolution is still as high as 0.007 nm, thus allowing accurate measurement of high-grade optical wavelength division multiplexers (WDM). This resolution enables chirps from modulated LDs as well as from Soliton transmission to be analyzed. The highest resolution of 0.001 nm is attained at a wavelength of about 500 nm and is particularly useful for the analysis of blue laser diodes. The indicated wave-length is always the value in a vacuum.
In addition to the wavelength display mode, frequency display can also be selected, with deviations being read out in GHz. The use of the Fourier spectroscopy enables true measurement of the coherence length. Q8347 allows a value of up to 165 mm to be analyzed. The evaluation itself is made automatically at a keystroke. In the spectral range a curve fitting function can be used. It directly shows the electroluminescence characteristic by fitting a Gaussian distribution into the emission spectrum a valuable aid in the measurement of erbium doped fiber amplifiers (EDFA), LDs and Soliton transmission systems.
