NIST Measurement Services: Measurement Assurance Program for the Spectral Densityof Relative Intensity Noise of Optical Fiber Sources Near 1550 nm

摘要

This paper provides the documentation to establish a measurement assuranceprogram (MAP) for the spectral density of relative intensity noise (RIN) of optical sources. A standard is made available to industry for high-precision calibration of RIN measurement systems. The device is an erbium-doped fiber amplifier (EDFA) to which is coupled a linear polarizer followed by a narrow pass-band optical filter. Measurements show that the spectral density of the RIN is invariant under attenuation and pump current, and constant from zero to many tens of gigahertz. These properties render it suitable as a standard for the calibration of high-speed systems. We characterize the device for use as a standard in the 1550nm wavelength range over a radio-frequency (rf) baseband of 0.1 GHz to 1.1 Ghz. For the typical device studied in depth, the magnitude of the RIN is 109.9 dB/Hz with uncertainty (< or =) 0.12 dB over the entire bandwidth. Since the behavior of the RIN standard can be determined from physical theory, we give a thorough derivation of the spectral density of RIN in the frequency representation. This derivation has been absent from the literature. We use this derivation to formulate the needed numerical RIN equations in spatial wavelength coordinates that are used to determine the RIN from optical power spectral density measurements made with a calibrated optical spectral analyzer.