HIGH-SENSITIVITY PRECISION RELATIVE INTENSITY NOISE CALIBRATION STANDARD USING LOW-NOISE REFERENCE LASER SOURCE

The intensity noise of laser diodes is an increasingly important param eter for broadband analogue and high data rate telecommunication syste ms. The authors describe a new primary calibration standard for measur ing the relative intensity noise (RIN) as a function of frequency (up to 20 GHz) with high sensitivities (< -171 dBm/Hz). In addition a new optical technique has been developed based on a low noise optical sour ce which provides an adjustable shot noise level. By comparing this fl at noise spectrum with the test spectrum the main traceable path is pr ovided by the measured DC photocurrent. Errors due to responsivity, ga in, mismatch etc., as a function of frequency are significantly reduce d and precisions of < 0.4 dB have been achieved.