High Frequency Optoelectronc Oscillator

Clocks and pulse sources are essential elements for radar systems. Timing control determines total system operation and the fundamental limitation for next generation sub-systems is clock jitter (phase noise). For multi GB/s systems, the clear choice is an optoelectronic oscillator in which the clock period is an optical delay. The phase noise is thereby reduced because the variability of the delay lies only in stability of the refractive index. The major source of phase noise then lies in the mechanism to adjust the clock period and the spontaneous noise on the optical source. Optoelectronic oscillators have been reported that use a collection of lasers , modulators, delays and RF amplifiers. Although phase noise is improved, the system is bulky and power consumptive. OPEL proposes an integrated version based upon a unique switching device that performs both as the optical source and detector. By integration with control HFETs and optical waveguides, the oscillator consumes minimal chip space and achieves phase noise approaching the quantum limit, since the RIN noise is that of the VCSEL (-160dB/Hz) and the control noise is only the shot noise on the injection current (<10fs jitter). In this SBIR, OPEL will produce the integrated OEO.