A I00 GHz AM and PM noise measurement system is described. The basic approach to its construction is to apply existing state-of-the-art, cross-correlation noise measurement techniques to IO0 GHz (W-band). The system uses two amplitude-noise and phase-noise detectors operating in parallel with cross-correlation spectrum analysis so that measurement-system… (More)
We utilized and characterized high-power, high-linearity modified unitraveling carrier (MUTC) photodiodes for low-phase-noise photonic microwave generation based on optical frequency division (OFD). When illuminated with picosecond pulses from a repetition-rate-multiplied gigahertz Ti:sapphire modelocked laser, the photodiodes can achieve a 10 GHz signal… (More)
High-quality frequency references are the cornerstones in position, navigation and timing applications of both scientific and commercial domains. Optomechanical oscillators, with direct coupling to continuous-wave light and non-material-limited f × Q product, are long regarded as a potential platform for frequency reference in radio-frequency-photonic… (More)
We demonstrate feedback and harmonic locking of chip-scale slot-type optomechanical oscillators to external low-noise reference clocks, with suppressed timing jitter by three orders of magnitude. The feedback and compensation techniques significantly reduce the close-to-carrier phase noise, especially within the locking bandwidth for the integral… (More)
—Precise timing in shared-user, wireless data communications systems directly affects the growing concern in establishing and managing 'spectrum harmony'. For shared spectrum, an efficient and widely accepted modulation type is orthogonal frequency division multiplexing (OFDM). The main advantage of OFDM to other modulation protocols is its efficient use of… (More)
1. Experimental setup for generation and cross-spectrum phase noise measurement of two 10 GHz hybrid microwave sources. LF denotes loop filter and PD denotes photodiode. Abstract— We demonstrate a 10 GHz hybrid oscillator comprised of a phase stabilized optical frequency comb divider and a room temperature dielectric sapphire oscillator. Characterization of… (More)
We demonstrate a novel technique for reducing the phase modulation (PM) noise of an oscillator in a steady-state condition as well as under vibration. It utilizes correlation between PM noise and amplitude modulation (AM) noise that can originate from the oscillator's loop components. A control voltage proportional to the correlated AM noise is generated… (More)
We describe operational challenges and progress of optical frequency-comb dividers (OFDs) that synthesize RF signals from the optical domain. Our priorities include: (1) ultra-low phase-noise, (2) continuous operation, and (3) broadly low Allan deviation.
— We present improved performance for a 92 – 96 GHz cross-spectrum phase modulated (PM) noise measurement system previously reported in . The system is principally designed to measure amplifiers in pulsed mode with a duty cycle of 10 % to 100 % (CW) at a given pulse repetition frequency. This paper reports only the CW mode of operation. Data for the… (More)
We discuss the design and performance of an all polarization-maintaining self-referenced frequency comb that can maintain optical coherence with an optical reference laser under strong vibrations from a shaker table and a moving vehicle.