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Tunable Laser Characteristics

Question asked by mkelly Employee on Feb 13, 2007
Latest reply on Feb 13, 2007 by agerster
Sometimes we are asked how to select a laser for sweep linearity.
Agilent has two main series of tunable laser sources.

If wavelength linearity is very important and is needed at the best possible level, we would recommend the 81600B series laser source over the 819xxA series compact laser source. But this depends on the level of performance needed.

The specified value that is closest to wavelength linearity is the relative wavelength uncertainty. For the 81600B, there are also specifications for this under "dynamic" (continuously swept) operation. Examples from the specifications are +/- 4.4pm at 5nm/s sweep and +/- 4.8pm at 40nm/s sweep. This applies to the variation over the complete laser wavelength range. For the variation over a range of about 10nm, we see typical performance below +/- 2pm.

The 81940A or 81980A compact tunables do not have detailed specifications for the dynamic conditions, but based on the static specification for relative wavelength uncertainty should be typically about 3-4 pm higher uncertainty.

The specifications for both types of tunable laser can be found on this web page.

Note that the above numbers apply when using the "lambda-logging" information from the tunable laser. The tunable laser measures its own wavelength during the sweep and records the values at the sample points, where the laser can output triggers to the power meters or other insturments, also externally.