46 research outputs found
Sideband Injection Locking in Microresonator Frequency Combs
Frequency combs from continuous-wave-driven Kerr-nonlinear microresonators
have evolved into a key photonic technology with applications from optical
communication to precision spectroscopy. Essential to many of these
applications is the control of the comb's defining parameters, i.e.,
carrier-envelope offset frequency and repetition rate. An elegant and
all-optical approach to controlling both degrees of freedom is the suitable
injection of a secondary continuous-wave laser into the resonator onto which
one of the comb lines locks. Here, we study experimentally such sideband
injection locking in microresonator soliton combs across a wide optical
bandwidth and derive analytic scaling laws for the locking range and repetition
rate control. As an application example, we demonstrate optical frequency
division and repetition rate phase-noise reduction to three orders of magnitude
below the noise of a free-running system. The presented results can guide the
design of sideband injection-locked, parametrically generated frequency combs
with opportunities for low-noise microwave generation, compact optical clocks
with simplified locking schemes and more generally, all-optically stabilized
frequency combs from Kerr-nonlinear resonators.Comment: 13 pages, 6 figure
Ultraviolet astronomical spectrograph calibration with laser frequency combs from nanophotonic waveguides
Astronomical precision spectroscopy underpins searches for life beyond Earth,
direct observation of the expanding Universe and constraining the potential
variability of physical constants across cosmological scales. Laser frequency
combs can provide the critically required accurate and precise calibration to
the astronomical spectrographs. For cosmological studies, extending the
calibration with such astrocombs to the ultraviolet spectral range is highly
desirable, however, strong material dispersion and large spectral separation
from the established infrared laser oscillators have made this exceedingly
challenging. Here, we demonstrate for the first time astronomical spectrograph
calibrations with an astrocomb in the ultraviolet spectral range below 400 nm.
This is accomplished via chip-integrated highly nonlinear photonics in
periodically-poled, nano-fabricated lithium niobate waveguides in conjunction
with a robust infrared electro-optic comb generator, as well as a
chip-integrated microresonator comb. These results demonstrate a viable route
towards astronomical precision spectroscopy in the ultraviolet and may
contribute to unlocking the full potential of next generation ground- and
future space-based astronomical instruments
Towards On-Chip Ultrafast Pulse Amplification
Amplification of ultrafast optical signals is key to a large number of applications in photonics. While ultashort pulse amplification is well established in optical gain fibers, it is challenging to achieve in photonic-chip integrated waveguides. Recently, several integrated (quasi-)continuous-wave amplifiers have been demonstrated, based on rare-earth, heterogeneous semiconductor integration or nonlinear parametric gain [1]–[4]. On-chip amplification of ultrafast pulses, however, remains challenging due to the inherently small mode area and high-optical nonlinearity in integrated waveguides
The CHEOPS mission
The CHaracterising ExOPlanet Satellite (CHEOPS) was selected in 2012, as the
first small mission in the ESA Science Programme and successfully launched in
December 2019. CHEOPS is a partnership between ESA and Switzerland with
important contributions by ten additional ESA Member States. CHEOPS is the
first mission dedicated to search for transits of exoplanets using ultrahigh
precision photometry on bright stars already known to host planets. As a
follow-up mission, CHEOPS is mainly dedicated to improving, whenever possible,
existing radii measurements or provide first accurate measurements for a subset
of those planets for which the mass has already been estimated from
ground-based spectroscopic surveys and to following phase curves. CHEOPS will
provide prime targets for future spectroscopic atmospheric characterisation.
Requirements on the photometric precision and stability have been derived for
stars with magnitudes ranging from 6 to 12 in the V band. In particular, CHEOPS
shall be able to detect Earth-size planets transiting G5 dwarf stars in the
magnitude range between 6 and 9 by achieving a photometric precision of 20 ppm
in 6 hours of integration. For K stars in the magnitude range between 9 and 12,
CHEOPS shall be able to detect transiting Neptune-size planets achieving a
photometric precision of 85 ppm in 3 hours of integration. This is achieved by
using a single, frame-transfer, back-illuminated CCD detector at the focal
plane assembly of a 33.5 cm diameter telescope. The 280 kg spacecraft has a
pointing accuracy of about 1 arcsec rms and orbits on a sun-synchronous
dusk-dawn orbit at 700 km altitude.
The nominal mission lifetime is 3.5 years. During this period, 20% of the
observing time is available to the community through a yearly call and a
discretionary time programme managed by ESA.Comment: Submitted to Experimental Astronom
Sideband Injection Locking in Microresonator Frequency Combs
Frequency combs from continuous-wave-driven Kerr-nonlinear microresonators have evolved into a key photonic technology with applications from optical communication to precision spectroscopy. Essential to many of these applications is the control of the comb’s defining parameters, i.e., carrier-envelope offset frequency and repetition rate. An elegant and all-optical approach to controlling both degrees of freedom is the suitable injection of a secondary continuous-wave laser into the resonator onto which one of the comb lines locks. Here, we study experimentally such sideband injection locking in microresonator soliton combs across a wide optical bandwidth and derive analytic scaling laws for the locking range and repetition rate control. As an application example, we demonstrate optical frequency division and repetition rate phase-noise reduction to three orders of magnitude below the noise of a free-running system. The presented results can guide the design of sideband injection-locked, parametrically generated frequency combs with opportunities for low-noise microwave generation, compact optical clocks with simplified locking schemes and more generally, all-optically stabilized frequency combs from Kerr-nonlinear resonators
Dual-Comb Spectroscopy for Astronomical Spectrograph Calibration
Precise and accurate calibration of astronomical spectrograph is key in exo-planet searches and cosmological studies. Dual-comb spectroscopy of a Fabry-Perot cavity represents a new approach to absolute calibration avoiding the need for high-repetition rate lasers
Diffractive optical elements in single crystal diamond
We demonstrate the design, fabrication, and experimental characterization of near-field binary phase transmission diffractive optical elements (DOEs) in single crystal diamond. Top-hat and arbitrary pattern DOE beam shapers were numerically optimized using an iterative Fourier transform algorithm (IFTA). Commercially available single crystal diamond plates (3 mm x 3 mm x 0.3 mm) were patterned using hardmask deposition (alpha-Si), e-beam lithography, and O-2 plasma-based diamond reactive ion etching. The resulting binary phase relief patterns were characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Experimental characterization of the single crystal diamond DOES in transmission at lambda = 532 nm confirms excellent uniformity of the resulting top-hat beam profile as required in copper welding applications. (C) 2020 Optical Society of Americ
Photo-acoustic dual-frequency comb spectroscopy
Here, the authors show that the resolution and speed limitations in broadband photo-acoustic spectroscopy can be overcome by combining dual-comb spectroscopy with photo-acoustic detection. This enables broadband detection and allows for rapid and sensitive multi-species molecular analysis across all wavelengths of light
Sideband injection locking in microresonator frequency combs
Frequency combs from continuous-wave-driven Kerr-nonlinear microresonators have evolved into a key photonic technology with applications from optical communication to precision spectroscopy. Essential to many of these applications is the control of the comb’s defining parameters, i.e., carrier-envelope offset frequency and repetition rate. An elegant and all-optical approach to controlling both degrees of freedom is the suitable injection of a secondary continuous-wave laser into the resonator onto which one of the comb lines locks. Here, we experimentally study such sideband injection locking in microresonator soliton combs across a wide optical bandwidth and derive analytic scaling laws for the locking range and repetition rate control. As an application example, we demonstrate optical frequency division and repetition rate phase-noise reduction to three orders of magnitude below the noise of a free-running system. The presented results can guide the design of sideband injection-locked, parametrically generated frequency combs with opportunities for low-noise microwave generation, compact optical clocks with simplified locking schemes, and, more generally, all-optically stabilized frequency combs from Kerr-nonlinear resonators