Agilent 81642A tunable laser repair

The Agilent 81642A is the high-power variant of the 81640A - same C-band tuning range, higher maximum output power for applications that need more optical drive into a DUT or through a lossy test path. It’s used in high-sensitivity component testing, optical amplifier gain measurements, and applications where low power would be masked by noise. Keysight support for the 81642A is discontinued.

The higher output power of the 81642A puts more thermal stress on the laser chip and TEC system than the 81640A. TEC failures show up as thermal runaway events that reduce output power and accuracy, or as degraded wavelength stability under long-running sweep conditions. Laser diode wear is accelerated in high-cycle environments where the module runs at full power continuously. Optical isolator degradation from high optical power handling is also seen - reduced back-reflection isolation can cause mode instability.

We test output power at maximum and mid-range set points, wavelength accuracy across the C-band, sweep quality, and thermal stability over a sustained run. TEC evaluation, laser assessment, isolator check, mainframe interface verification, and NIST-traceable wavelength calibration complete the service.

Flat-rate estimate: $100. Turnaround 1–3 days. Ships worldwide.