Search results for "Frequency comb"
showing 10 items of 27 documents
A new Collinear Apparatus for Laser Spectroscopy and Applied Science (COALA).
2020
We present a new collinear laser spectroscopy setup that has been designed to overcome systematic uncertainty limits arising from high-voltage and frequency measurements, beam superposition, and collisions with residual gas that are present in other installations utilizing this technique. The applied methods and experimental realizations are described, including an active stabilization of the ion-source potential, new types of ion sources that have not been used for collinear laser spectroscopy so far, dedicated installations for pump-and-probe measurements, and a versatile laser system referenced to a frequency comb. The advanced setup enables us to routinely determine transition frequenci…
Generation and Coherent Control of Pulsed Quantum Frequency Combs
2018
We present a method for the generation and coherent manipulation of pulsed quantum frequency combs. Until now, methods of preparing high-dimensional states on-chip in a practical way have remained elusive due to the increasing complexity of the quantum circuitry needed to prepare and process such states. Here, we outline how high-dimensional, frequency-bin entangled, two-photon states can be generated at a stable, high generation rate by using a nested-cavity, actively mode-locked excitation of a nonlinear micro-cavity. This technique is used to produce pulsed quantum frequency combs. Moreover, we present how the quantum states can be coherently manipulated using standard telecommunications…
Frequency comb generation in whispering gallery mode silica microsphere resonators
2021
Optical frequency combs (OFC) using different kinds of whispering-gallery-mode (WGM) microresonators have already shown different applications and especially their applications in fiber optical communication systems as replacements of laser-arrays. For this application the free spectral range (FSR) of 200 GHz or less is desirable. Besides the fabrication material for microspheres, the resonator radius can be modified to change the FSR. In this paper use of silica microspheres for OFC represents an inexpensive alternative over the other microcombs: microring, microdisk, and microtoroid. We experimentally present a microsphere fabrication process from a different kind of silica (SiO2) fibers …
Iodine hyperfine structure and absolute frequency measurements at 565, 576, and 585nm
2006
Abstract The hyperfine structure splittings of the P(10)14-1, R(15)14-1, and R(99)15-1 transitions at 585 nm, P(62)17-1 at 576 nm, and P(80)21-1 at 565 nm in 127 I 2 are measured by heterodyne spectroscopy using two dye lasers. In addition, the absolute frequencies of the hyperfine components P(10)14-1 a 15 and P(80)21-1 a 10 are determined using a self-referenced frequency comb. These frequencies are used in an experiment testing relativistic time dilation by laser spectroscopy on a fast ion beam.
Squeezing in Kerr-like cavities: optomechanics, polariton microcavities and superconducting circuits
2017
Aquesta tesi està dedicada fonamentalment a l’estudi teòric de la generació d’estats comprimits de la llum mitjançant cavitats òptiques tipus Kerr amb un bombeig bicromàtic. Bàsicament amb aquest tipus d’injecció fem que la usual corba de biestabilitiat observada en la dinàmica no lineal d’aquests sistemes amb injecció monocromàtica, canvie a una bifurcació tipus forca, degut a un fenòmen de mescla de quatre ones. A prop de l’esmentada bifurcació les fluctuacions quàntiques del camp electromagnètic són modificades de forma que l’estat quàntic de la llum a l’eixida de la cavitat és d’un buit comprimit. En aquesta introducció explicarem breument que és aquesta compressió de la llum, que són l…
Dual-Comb Spectroscopy With Frequency-Agile Lasers
2015
Multiheterodyne frequency comb spectroscopy without mode-locked lasers is reported in the near-infrared C and L telecommunication bands. The system without active stabilization combines high signal-to-noise ratio, rapid tuning and moderate multiplex spectral span.
On-chip quantum frequency combs for complex photon state generation (Conference Presentation)
2020
A key challenge in today’s quantum science is the realization of large-scale complex non-classical systems to enable e.g. ultra-secure communications, quantum-enhanced measurements, and computations faster than classical approaches. Optical frequency combs represent a powerful approach towards this, since they provide a very high number of temporal and frequency modes which can result in large-scale quantum systems. Here, we discuss the recent progress on the realization of integrated quantum frequency combs and reveal how their use in combination with on-chip and fiber-optic telecommunications components can enable quantum state control with new functionalities, yielding unprecedented capa…
Absolute frequency measurement of rubidium 5S-7S two-photon transitions.
2013
We report the absolute frequency measurements of rubidium 5S-7S two-photon transitions with a cw laser digitally locked to an atomic transition and referenced to an optical frequency comb. The narrow, two-photon transition, 5S-7S (760 nm) insensitive to first order in a magnetic field, is a promising candidate for frequency reference. The performed tests yield the transition frequency with accuracy better than reported previously.
Frequency-comb-based measurements of lithium and beryllium isotopes for nuclear structure studiesThis paper was presented at the International Confer…
2009
We report on the measurement of the 2s-3s transition frequencies in the stable lithium isotopes and 2s-2p isotope shift measurements of 7,9,10,11Be, using a femtosecond frequency comb. For the beryllium isotopes, we extract the changes in the mean-square nuclear charge radius along the isotope chain by comparison with high-precision atomic mass shift calculations. The 2s-3s transition frequency is compared with theoretical calculations, and possibilities to extract an absolute value for the nuclear charge radius of lithium isotopes are discussed.
Triply resonant coherent four-wave mixing in silicon nitride microresonators
2015
The generation of multiple tones using four-wave mixing (FWM) has been exploited for many applications, ranging from wavelength conversion to frequency comb generation. FWM is a coherent process, meaning that its dynamics strongly depends on the relative phase among the waves involved. The coherent nature of FWM has been exploited for phase-sensitive processing in different waveguide structures, but it has never been studied in integrated microresonators. Waveguides arranged in a resonant way allow for an effective increase in the wavelength conversion efficiency (at the expense of a reduction in the operational bandwidth). In this letter, we show that phase shaping of a three-wave pump pro…