Agilent Technologies 86140B Series, User Manual

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7-19
Specifications and Regulatory Information
Specifications
Option 006 Wavelength Calibrator
The wavelength calibrator option provides an onboard wavelength reference
that can be used to automatically calibrate the optical spectrum analyzer. The
calibrator is based on an EELED and an Acetylene gas absorption cell.
Wavelength Calibrator Block Diagram
The acetylene absorbs light at very specific wavelengths based on the molecu-
lar properties of gas. The cell is illuminated by an EELED and the OSA uses
the absorption pits to perform a wavelength calibration. Since the absorption
of the acetylene gas is a physical constant, it never needs calibrating.
Wavelength calibrator absorption spectrum
The wavelength calibrator enhances the OSA to achieve better than
±
10 pm
wavelength accuracy and removes the need to use a tunable laser source and
multi-wavelength meter as an external reference.