A5011446206- Advanced Frequency and Time Standards
- Advanced Fiber Laser Technologies
- Photonic and Optical Devices
- Radio Frequency Integrated Circuit Design
- Advanced Photonic Communication Systems
- Advancements in PLL and VCO Technologies
- Mechanical and Optical Resonators
- Acoustic Wave Resonator Technologies
- Semiconductor Lasers and Optical Devices
- Advanced Fiber Optic Sensors
- Advanced Electrical Measurement Techniques
- Atomic and Subatomic Physics Research
- Superconducting and THz Device Technology
- Microwave and Dielectric Measurement Techniques
- Advanced MEMS and NEMS Technologies
- Cold Atom Physics and Bose-Einstein Condensates
- Optical Network Technologies
- Spectroscopy and Laser Applications
- Indoor and Outdoor Localization Technologies
- Quantum optics and atomic interactions
- Gyrotron and Vacuum Electronics Research
- Bluetooth and Wireless Communication Technologies
- Scientific Measurement and Uncertainty Evaluation
- Blind Source Separation Techniques
- Semiconductor Quantum Structures and Devices
National Institute of Standards and Technology
2015-2024
United States Department of Commerce
2011
University of Burdwan
1997-2004
Fluctuations of the optical power incident on a photodiode can be converted into phase fluctuations resulting electronic signal due to nonlinear saturation in semiconductor. This impacts overall timing stability (phase noise) microwave signals generated from photodetected pulse train. In this paper, we describe and utilize techniques characterize conversion amplitude noise for several high-speed (>10 GHz) InGaAs P-I-N photodiodes operated at 900 nm. We focus impact effect photonic generation...
We demonstrate a self-referenced fiber frequency comb that can operate outside the well-controlled optical laboratory. The has residual linewidths of < 1 Hz, sub-radian phase noise, and pulse-to-pulse timing jitter 2.4 - 5 fs, when locked to an reference. This fully phase-locked been successfully operated in moving vehicle with 0.5 g peak accelerations on shaker table sustained rms integrated acceleration, while retaining its coherence 5-fs-level jitter. should enable metrological...
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 can achieve 10 GHz signal power of +14 dBm. Using these diodes, we generated tone less than 500 attoseconds absolute integrated timing jitter (1 Hz–10 MHz) phase noise floor −177...
Abstract Fundamental science, as well all communications and navigation systems, are heavily reliant on the phase, timing, synchronization provided by low‐noise agile frequency sources. Although research into varied photonic electronic schemes have strived to improve upon spectral purity of microwave millimeter‐wave signals, reliance conventional synthesis for tuning has resulted in limited progress broadband Using a digital‐photonic synthesizer architecture that derives its time‐base from...
We present an optical-electronic approach to generating microwave signals with high spectral purity. By circumventing shot noise and operating near fundamental thermal limits, we demonstrate 10 GHz absolute timing jitter for a single hybrid oscillator of 420 attoseconds (1Hz - 5 GHz).
Cross-spectral analysis is a mathematical tool for extracting the power spectral density of correlated signal from two time series in presence uncorrelated interfering signals. We demonstrate and explain set amplitude phase conditions where detection desired using cross-spectral fails partially or entirely second signal. Not understanding when how this effect occurs can lead to dramatic under-reporting Theoretical, simulated experimental demonstrations as well mitigating methods are presented.
High-quality frequency references are the cornerstones in position, navigation and timing applications of both scientific commercial domains. Optomechanical oscillators, with direct coupling to continuous-wave light non-material-limited f × Q product, long regarded as a potential platform for reference radio-frequency-photonic architectures. However, one major challenge is compatibility standard CMOS fabrication processes while maintaining optomechanical high quality performance. Here we...
This paper addresses two issues: (i) it compares the usefulness of phase-modulation (PM) noise measurements vs. figure (NF) in characterizing merit an amplifier, and (ii) reconciles a general misunderstanding using -174 dBc/Hz (relative to carrier input power 0 dBm) as thermal level. The residual broadband (white PM) is used basis for estimating amplifier. We have observed experimentally that many amplifiers show increase 1 5 dB signal level through amplifier increases. effect linked...
We present the design of a novel, ultralow-phasenoise frequency synthesizer implemented with extremely-lownoise regenerative dividers. This generates eight outputs, viz. 1.6 GHz, 320 MHz, 160 80 40 20 10 MHz and 5 for an 8 GHz input frequency. The residual single-sideband (SSB) phase noises at outputs 1 Hz offset from carrier are -150 -145 dBc/Hz, respectively, which unprecedented noise levels. also report lowest values to date RF signals achieved our by dividing signal generated...
Coherent frequency division of high-stability optical sources permits the extraction microwave signals with ultra-low phase noise, enabling their application to systems stringent timing precision. To date, highest performance have required tight stabilization laboratory grade combs Fabry–Pérot reference cavities for faithful optical-to-microwave division. This requirement limits technology highly controlled environments. Here, we employ a transfer oscillator technique, which employs digital...
We report exceptionally low PM noise levels from a microwave oscillator that uses conventional air-dielectric cavity resonator as frequency discriminator. Our approach is to increase the discriminator's intrinsic signal-to-noise ratio by use of high-power carrier signal interrogate an optimally coupled cavity, while high-level suppressed before phase detector. developed and tested accurate model expected indicates, among other things, moderate Q will exhibit less discriminator in this than...
This paper primarily addresses the usefulness of phase-modulation (PM) noise measurements versus figure (NF) in characterizing merit an amplifier. The residual broadband (white PM) is used as basis for estimating NF We have observed experimentally that many amplifiers show increase 1 to 5 dB signal level through amplifier increases. effect linked input power amplifier's nonlinear intermodulation distortion. Consequently, this reduced linearity increased. further conclude that, although...
This study compares the phase noise of different classes oscillators and amplifiers that work at X-band. Best-in-class results are presented based on recent measurements NIST. In particular, comparisons made between mature technologies multiplied quartz, sapphire dielectric in whispering gallery mode (WGM), air-dielectric-resonator stabilized RF contrast to various configurations optical electronic (OEO), cavity-stabilized, atom-stabilized optical-domain femtosecond-lasercomb frequency...
We report on the first deployment of a ytterbium (Yb) transportable optical lattice clock (TOLC), commercially shipping 3000 km from Boulder, Colorado, to Washington DC. The system, composed rigidly mounted reference cavity, an atomic physics package, and frequency comb, fully realizes independent standard for comparisons in microwave domains. shipped Yb TOLC was operational within 2 days arrival, enabling comparison with rubidium (Rb) fountain at United States Naval Observatory (USNO). To...
Optoelectronic oscillators (OEO) are unique compared to radio-frequency (RF) in that they do not fundamentally require a RF gain element order satisfy the amplitude threshold condition for oscillation. All of energy required oscillation can be obtained from optical carrier. This, however, was initially possible, due inefficiency and power limitations on components used OEO. Recent improvements driven by need optical-RF links have improved modulator detector technology. Electro-optic...
This paper demonstrates direct detection of weak signals at microwave frequencies based on parametric frequency conversion. The atomic medium is optically pumped by a resonant light field and prepared in coherent superposition field. causes modulation the polarization probe frequency. An upper limit magnetic component sensitivity 1.2(1.0) pT/Hz <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1/2</sup> , corresponding to 3.7(3.1)-μV/cm/Hz...
Cross-spectrum analysis is a commonly-used technique for the detection of phase and amplitude noise signal in presence interfering noise. It extracts desired correlated from two time series uncorrelated Recently, we demonstrated that phase-inversion (anti-correlation) effect due to AM leakage can cause complete or partial collapse cross-spectral function. In this paper, discuss newly discovered anti-correlated thermal originates common-mode power divider (splitter), an essential component...
<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> We propose and experimentally demonstrate a novel technique to reduce laser relative intensity noise (RIN). A RIN suppression servo is usually implemented by inserting an modulator in the optical path controlling measured light with closed-loop system. utilize already present photonic link perform task of as well encoding signal microwave subcarrier. This provides 10 50 dB over bandwidth MHz....
We derive expressions for the group velocities of transverse electric and magnetic electromagnetic waves in a stretched single-mode fiber. Stretching can occur either as result temperature changes spool on which fiber is wound, or axial vibrations that accelerate hence deform spool. Long fibers are typically used optoelectronic oscillators, where velocity plays central role determining oscillator frequencies. The present idealized calculation assumes there fractional length change deltal/l,...
<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> Vibration causes mechanical distortions in optical fibers that induce phase fluctuations the transmitted signal. Information encoded on signal by modulation, such as a radio-frequency (RF)-photonic link also degrades. A feed-forward correction technique is described enables 20 dB or more cancellation of vibration-induced an fiber wound spool. The scheme applied to optoelectronic oscillator (OEO)....
The performance of microwave components is sensitive to vibrations some extent. Aside from the resonator, cables, and connectors, bandpass filters, mechanical phase shifters, nonlinear are most sensitive. local oscillator one prime performance-limiting in systems ranging simple RF receivers advanced radars. increasing present future demand for low acceleration oscillators, approaching 10(-13)/g, requires a reexamination sensitivities basic nonoscillatory building-block under vibration....
We describe the development and frequency instability measurements of a highly miniaturized, buffer gas cooled, trapped-ion atomic clock. The clock utilizes 12.6 GHz hyperfine transition <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">171</sup> Yb xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> ion. A custom-built 3 cm xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> vacuum package containing ion trap is integrated with other key elements...
We present data that show correlations between phase fluctuations in a low g-sensitive 10 MHz oven-controlled quartz oscillator (OCXO) and acceleration/vibration sensors. describe the equipment setup measurement procedure. Data are form of scatter plots, which we find to be highly informative compared usual L(f) plots when is subjected vibration.