Patent ID: 8879054

Claim:
An apparatus comprising: a source for generating an optical test signal sweeping a bandwidth of wavelengths over time, the test signal for application to a device under test (DUT) to generate a response signal from the DUT; a timing signal generator connected to the source for generating a timing signal, the timing signal having triggers generated at time instances corresponding to known wavelengths of the test signal; a DUT detector for sampling the DUT response signal to generate sampled DUT data, the DUT detector having a sampling period that is shorter than a shortest time between timing signal triggers; a correlator for receiving the timing signal, the known wavelengths associated with the timing signal triggers, the sampled DUT data and the DUT detector sampling period, the correlator for correlating each sampled DUT datum to a wavelength of the test signal that was applied to the DUT when the DUT datum was sampled by interpolating the known wavelengths using the trigger time instances and the DUT detector sampling period.