Advantest Q7761 Optical Network Analyzer

In recent years, progress in the research and development of ultra-high-speed optical transmission and high-density wavelength division multiplexing transmission (Dense WDM) has been enormous. This research and development requires the measurement of amplitude characteristics, chromatic dispersion, and group delay time of optical devices and optical subsystems with high optical frequency resolution. Examples of devices for which such characteristics must be measured are AWGs, Fibre Bragg Gratings filters, attenators, couplers, isolaters, fibers and dispersion compensators. Because dispersion characteristics in particular are an obstacle when optical transmission bit rate increases, chromatic and polarisation mode dispersion values as well as 2nd PMD must be decreased and controlled. The Q7761 is an optical network analyser capable of measuring many characteristics of optical devices at highest resolution and highest speed in the optical carrier frequency domain. It can measure amplitude characteristics, group delay time, chromatic dispersion CD, polarisation mode dispersion PMD and 2nd PMD too as well as PDL. The Q7761 employs the polarisation phase-shift method of measurement to achieve both high optical frequency resolution and wide dynamic range.

The Q7761 uses a fast tunable light source. By sweeping the wavelength (optical frequency), transmission characteristics can be measured. The Q7760 can measure the a.m. parameters simultaneously in one single sweep. And also fiber length can be measured up to 10.000 km.

Features

• Comprehensive measurement of optical transfer characteristics in the optical carrier frequency domain, enabling the design and verification of components, fibers and systems for 10 Gbit/s, 40 Gbit/s and more
  
• Measurement wavelength range: 1525 nm to 1625 nm
  
• Wavelength setting range 1 pm with ± 1,5 pm accuray using the Q8326 wavelength meter, which allows the evaluation of components for 100, 50 and 25 GHz channel spacing
  
• High-speed measurement: Approx. 1.5 seconds (at 1nm sweep span)
  
• Measurement points up to 12.000
  
• Dynamic range of 60 dB
  
• Chromatic dispersion measurement with resolution 0.1 ps/nm
  
• Polarisation mode dispersion measurement with 60 fs accuracy
  
• Group delay measurement with a maximum resolution of 1 fs
  
• Fiber length 0,2 m to 10.000 km with 0,01% resolution
• Big 12" screen with up to 4 windows, VGA, GPIB, LAN, USB and printer interfaces, floppy disc drive for traces/settings/Bitmap saving, optical connector FC/PC or ST.
  

Application

Design and manufacturing test of passive and active optical components like:

• All kinds of optical filters like Fiber Bragg Grating FBG, Array Waveguide Gratings AWG, interleavers, splitters, gain equalizers
  
• Dispersion Compensators
  
• Optical amplifiers
• SMF/DCF/DSF/Non-zero Dispersion Fibers, EDF, EDF, PCF, RDF, PMF

Example of report form of measurement results for every measuring point, including wavelength, group delay, fitted group delay, chromatic dispersion and CD slope

Limit line function for Pass/Fall analysis on amplitude characteristic

Reflection amplitude and polarisation mode dispersion characteristics of FBG optical filter for 100 GHz spacing, showing the periodic ripple in the PMD

Group Delay Characteristics of an AWG Optical Demultiplexer - reveals a gradual change in the group delay within the optical pass band

Group delay, CD and Zero-dispersion wavelength of a dispersion shifted fiber (DSF)