The heterodyne laser microwave fiberoptic link configuration takes advantage of the undesirable laser diode nonlinearities to operate the semiconductor laser as an optical source and a microwave mixer simultaneously. A cost-effective microwave heterodyne laser fiberoptic link using low-cost multimode optical fiber and components will be described. The experimental results of several microwave heterodyne laser fiberoptic links are also to be presented. For example, a system signal-to-noise ratio of 115 dB/Hz has been obtained, without any special system/circuit optimization, for a 1 km X-band fiberoptic link using a multimode fiber cable, an inexpensive 1.4 GHz laser diode, a low frequency photo-detector, and an IF post-detector amplifier.
J J. Pan, J J. Pan,
"Cost-Effective Microwave Fiberoptic Links Using The Heterodyne Laser", Proc. SPIE 0995, High Frequency Analog Communications, (17 January 1989); doi: 10.1117/12.960149; https://doi.org/10.1117/12.960149