TIA TIA-455-228

ALSO SEE NECA NEIS 301

In this procedure, a modulated light source at a givenwavelength is coupled into the component under test, and the phaseshift of the modulated signal exiting the fiber at that wavelengthis recorded with respect to the original modulation signal. Thephase shift can be converted directly to RGD in the device. Bycollecting RGD data at various wavelengths, the chromaticdispersion of the component can be determined at these and otherwavelengths from the derivative with respect to wavelength of therelative group delay.

This FOTP does not apply to components that have in excess of 10dB of polarization dependent loss (PDL). The main intent of thisFOTP is to determine the average group delay and chromaticdispersion of the component and moreover to isolate the RGD fromall polarization sensitivity in the device.

Note that in the case of fiber pigtailed components, thepigtails may give a large absolute (standing) delay but also somerelative delay, over the component test wavelength range. In mostcases of component measurements, only the relative group delay isof interest, so it is important to account for any RGD in theleads, and to ensure the standing delay is stable over themeasurement time. Any changes in the standing delay and any RGD inthe leads will be evident in the test results.

Edition:

02

Published:

02/01/2002

Number of Pages:

50