User`s guide

Performance Tests Power Tests
116 Agilent 81600B Tunable Laser Source Family, Fourth Edition
Signal-to-Source Spontaneous Emission
Ratio - Low SSE Output
The setup described by “Signal-to-Source Spontaneous Emission Ratio”
on page 112 is limited by the dynamic range of the Optical Spectrum
Analyzer. This can be improved by reducing the power of the spectral line
of the TLS module using a filter, namely a Fiber Bragg Grating. However,
this approach limits the measurement to a single wavelength, that of the
the peak attenuation of the Fiber Bragg Grating.
Figure 36 Transmission Characteristics of Fiber Bragg Grating
Wavelength measurement mismatch between TLS and OSA
Because the Tunable Laser channel displays the wavelength in air and the
Optical Spectrum Analyzer displays the wavelength in vacuum there is a
mismatch between the values displayed by the two instruments.
A good approximation in this wavelength range is:
λ
OSA
= λ
TLS
- 0.5 nm
Use
λ
TLS
as the primary reference because the specified wavelength
accuracy of the TLS module is better than that of the OSA.
The accuracy of the offset value in this equation does not influence the
accuracy of the spectral and total SSE measurements.
NOTE