Publications by authors named "Afshin S Daryoush"

Optoelectronic oscillators (OEOs) with their demonstrated low phase noise are popular due to the increasing demand of very clean local oscillator and clock signal sources. A forced technique of self-injection locked and phase-locked loop (SILPLL) reduces phase noise and suppresses side mode observed in long fiber delay of the standard OEO. A frequency synthesizer working at X -band is developed using an electrically coarse-tuned YIG filter cascaded with an optical wavelength fine-tuned dispersive optical transversal filter by tuning the oscillation frequency of the synthesized OEO frequency, as a replacement for fixed-frequency narrowband filter using high- Q aluminum cavities.

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Forced oscillation based on self-injection locked phase-locked (SILPLL) opto-electronic oscillator (OEO) technique is the basis of highly stable and low phase noise oscillators to be used as a key component in modern communication and sensing systems. To avoid large-size modular OEO, inter-modal oscillation at X-band frequencies is achieved in a compact multi-mode multi-section semiconductor laser using InP foundry service. Self-forced oscillation technique of SILPLL is demonstrated, where a phase noise performance of -98 dBc/Hz is measured at 10 kHz offset carrier of 11 GHz, which is an improvement of 68 dB compared with the free-running condition, which corresponds with 600 times reduction in calculated timing jitters from the free-running case to reach 0.

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Our purpose is to improve the performance sensitivity of a fiber sensor used as a fiber optic hydrophone probe (FOHP) by the addition of nanoscale thin film gold coating. The fiber is designed to provide a uniform and spatial averaging free response up to 100 MHz by etching down to an active diameter of approximately 9 mum. The performance sensitivity of straight cleaved (i.

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