For example: Agilent E4440A or Anritsu 68369
Keysight / Agilent Optical Spectrum Analyzers
Keysight / Agilent 70950B
OPTICAL SPECTRUM ANALYZER MODULE RANGE 600 - 1700 nm
Manufacturer: Keysight / Agilent
Keysight / Agilent 70952B
Agilent 70952B Optical Spectrum Analyzer Module
Manufacturer: Keysight / Agilent
Keysight / Agilent 83496A
Optical / Electrical clock recovery module, 50 Mb/s – 7.1 Gb/s
Manufacturer: Keysight / Agilent
Keysight / Agilent 83496B
Optical/Electrical Clock Recovery Module With Phase Noise Analysis Capability
Manufacturer: Keysight / Agilent
Keysight / Agilent 86116B
86116B 65 GHz optical / 80 GHz electrical module
Manufacturer: Keysight / Agilent
Keysight / Agilent 86140A
Standard Benchtop Optical Spectrum Analyzer
Manufacturer: Keysight / Agilent
Keysight / Agilent 86143A
86143A Portable Standard Performance Optical Spectrum Analyzer
Manufacturer: Keysight / Agilent
Keysight / Agilent 86143B
Portable Standard Performance Optical Spectrum Analyzer
Manufacturer: Keysight / Agilent
Keysight / Agilent 86144B
Portable Standard Optical Spectrum Analyzer with Filter Mode [Discontinued]
Manufacturer: Keysight / Agilent