Low-loss 1.3-μm MQW electroabsorption modulators for high-linearity analog optical links

Low-loss InAsP-GaInP multiquantum-well electroabsorption waveguide modulators have been developed for transmitting microwaves as subcarriers over optical fibers. The fiber-to-fiber insertion loss is only 5 dB at 1.32-mu m wavelength. The electrooptic slope efficiency of an 185-mu m-long 11-GHz bandwidth device is equivalent to a Mach-Zehnder modulator with a V-pi of 2.2 V, The linearity performance was characterized for a test link without any form of amplification. A RF-to-RF link efficiency of -25.5 dB, noise figure of 27 dB and suboctave spurious-free dynamic range of 114 dB . Hz(4/5) have been achieved with 16-mW input optical carrier power, The measured 3-dB electrical bandwidth exceeds 20 GHz for a 90-mu m-long device.