Frequency Combs for Spectroscopy and Optical Metrology

Frequency Combs for Spectroscopy and Optical Metrology
Author: Md Imrul Kayes
Publisher:
Total Pages:
Release: 2019
Genre:
ISBN:

"Since their inception, optical frequency combs have created novel avenues for numerous applications such as molecular spectroscopy, atomic clocks, coherent communications, and microwave photonics. The future of frequency combs lies in exploring different comb generation technique, customized for specific applications. This thesis explores the synthesis of novel optical frequency combs in the near infrared wavelength region and the applications of such combs in the field of high-resolution spectroscopy and precise distance measurement. First, the generation of an electro-optic frequency comb with adjustable central wavelength and frequency spacing is experimentally demonstrated. This frequency comb is sourced from a single mode Brillouin fiber laser having an ultra-narrow linewidth that improves the overall phase noise performance of the comb spectral lines. A combined effect of electro-optic modulation, dispersion compensation, and fiber nonlinearity convert the continuous wave laser into a wideband optical frequency comb encompassing the C-band. Next, this frequency comb is used for a high-resolution distance measurement system that operates from the repetition rate modulation of the comb signal. The repetition frequency of the electro-optic comb is adjustable with a high dynamic range. Such broad tunablity of the repetition rate facilitates the measurement of distances with μm level precision. Such a system is also capable of motion tracking thanks to the rapid scan rate of the repetition frequency. Next, the application of electro-optic combs in high-resolution Fourier transform spectroscopy is demonstrated by measuring absorption lines of a chemical sample at 1.55 μm. The pulse train from a frequency comb, subject to a repetition rate modulation, stores the spectral response of a sample when sent to a length imbalanced interferometer. Such a system is equivalent to a dual-comb spectrometer but without the need for a complex phase matching mechanism. Finally, a novel laser resonator is developed for high-resolution dual-comb spectroscopy at 1.9 μm. This resonator supports two counter-propagating laser oscillations sharing a common cavity which relaxes the phase matching requirement for dual-comb spectroscopy. A proof-of-concept experiment demonstrated the measurement of absorption lines of ambient water vapor with a 100 MHz resolution. This approach holds great promise for dual-comb spectroscopy in the mid-infrared region where many chemicals have strong fundamental transitions"--

Femtosecond Optical Frequency Comb: Principle, Operation and Applications

Femtosecond Optical Frequency Comb: Principle, Operation and Applications
Author: Jun Ye
Publisher: Springer Science & Business Media
Total Pages: 373
Release: 2006-06-15
Genre: Science
ISBN: 0387237917

Over the last few years, there has been a convergence between the fields of ultrafast science, nonlinear optics, optical frequency metrology, and precision laser spectroscopy. These fields have been developing largely independently since the birth of the laser, reaching remarkable levels of performance. On the ultrafast frontier, pulses of only a few cycles long have been produced, while in optical spectroscopy, the precision and resolution have reached one part in Although these two achievements appear to be completely disconnected, advances in nonlinear optics provided the essential link between them. The resulting convergence has enabled unprecedented advances in the control of the electric field of the pulses produced by femtosecond mode-locked lasers. The corresponding spectrum consists of a comb of sharp spectral lines with well-defined frequencies. These new techniques and capabilities are generally known as “femtosecond comb technology. ” They have had dramatic impact on the diverse fields of precision measurement and extreme nonlinear optical physics. The historical background for these developments is provided in the Foreword by two of the pioneers of laser spectroscopy, John Hall and Theodor Hänsch. Indeed the developments described in this book were foreshadowed by Hänsch’s early work in the 1970s when he used picosecond pulses to demonstrate the connection between the time and frequency domains in laser spectroscopy. This work complemented the advances in precision laser stabilization developed by Hall.

Temporal Characterisation of Optical Frequency Combs

Temporal Characterisation of Optical Frequency Combs
Author: Chaitanya Suhas Joshi
Publisher:
Total Pages: 53
Release: 2013
Genre:
ISBN:

The emerging field of silicon photonics allows us to develop more efficient networks that go beyond the capabilities and limitations of current electronic networks. Integrated photonic solutions in the present and in the future will allow us to keep pace with Moore's Law. Expertise in Silicon fabrication is at a very advanced level due to its use in semiconductor electronics. This expertise can be applied directly to fabricating optical devices using silicon as a medium of propagation for light. Silicon shows a high non linear optical response with high intensities. The high intensities required to see non linearity can be achieved by using waveguides etched into the silicon which confine light to a small mode area thus increasing intensity. One application for silicon waveguide devices is the development of frequency combs. A frequency comb can act as an accurate frequency standard over a very large bandwidth that can range from the visible all the way through to the Mid IR. Applications for frequency combs can be found in high precision spectroscopy, optical metrology, highly precise optical atomic clocks and so on. By the very nature of its frequency spectrum, we expect to see short pulses in the temporal domain from a frequency comb. This thesis examines the building of an autocorrelation setup that can measure these pulses to high accuracy. We explore the choice of detection scheme, the choice of setup and go on to discuss some results from the setup that was built as part of the work leading up to this date.

Optical Frequency Combs

Optical Frequency Combs
Author: Auro Michele Perego
Publisher: CRC Press
Total Pages: 0
Release: 2024-07-31
Genre: Science
ISBN: 9781032548081

"In this book we will discuss both the operating principles and performance limits of a wide range of device technologies, and the technological requirements of applications. We will identify close synergies where technology capabilities and application requirements are closely aligned, and opportunities for generic optical frequency combs where multiple solutions and applications exist simultaneously. The main topics to be covered will include:(i) Different sources and methods of optical frequency combs generation including mode-locked lasers, optical resonators, opto-electronics, and nonlinear fibres. (ii) Applications of optical frequency combs in different technologies including sensing, spectroscopy, metrology, distance ranging and optical communications. (iii) Blue-sky novel physical concepts and promising future research directions for the field. With this book we aim at showcasing top level advances by key players in a multifaceted research ecosystem, and at the same time at providing a valuable service to our research community, by offering a comprehensive review which, at the same time, highlights challenges to be solved and promising future directions. This book will be a valuable resource for academics and researchers working in optical frequency combs, and more broadly in photonics and laser physics. It will also be of interest to postgraduate and graduate students of photonics and laser physics"

Frequency Measurement and Control

Frequency Measurement and Control
Author: Andre N. Luiten
Publisher: Springer
Total Pages: 397
Release: 2014-03-12
Genre: Technology & Engineering
ISBN: 9783662307953

This text on precision frequency measurement and its key enabling techniques includes reviews written by some of the most experienced researchers in their respective fields. This text should prove useful to researchers just entering the field of frequency metrology and standards, or equally well to the experienced practitioner.

All-fiber Frequency Comb Employing a Single Walled Carbon Nanotube Saturable Absorber for Optical Frequency Metrology in Near Infrared

All-fiber Frequency Comb Employing a Single Walled Carbon Nanotube Saturable Absorber for Optical Frequency Metrology in Near Infrared
Author: Jinkang Lim
Publisher:
Total Pages:
Release: 2011
Genre:
ISBN:

Optical frequency combs produced by mode-locked fiber lasers are useful tools for high precision frequency metrology and molecular spectroscopy in a robust and portable format. We have specifically investigated erbium doped fiber mode-locked lasers that use single-walled carbon nanotubes as a saturable absorber. We have, for the first time, developed and phase- stabilized a carbon nanotube fiber laser (CNFL) frequency comb. The carbon nanotube saturable absorber, which was fabricated using an optically driven deposition method, permits a high repetition frequency (>150 MHz) since an optical nonlinearity of fibers is not used for mode-locking. The CNFL comb combined with a parabolic pulse erbium doped fiber amplifier (EDFA) has shown a compact, robust, and cost-effective supercontinuum source. The amplified pulse from the parabolic pulse EDFA was compressed with a hollow-core photonic bandgap fiber, which produced a wave-breaking-free pulse with an all-fiber set-up. The stabilized comb has demonstrated a fractional instability of 1.2 ©--10[superscript]-11 at 1 sec averaging time, the reference-limited instability. We have performed optical frequency metrology with the CNFL comb and have measured an optical frequency, P(13) which is a molecular overtone transition of C2H2. The measured frequency has shown a good agreement with the known value within an uncertainty of 10 kHz. In order to extend the application of the CNFL comb such as multi-heterodyne dual comb spectroscopy, we have investigated the noise of the CNFL comb and particularly, the broad carrier envelope offset frequency (f[subscript]0) linewidth of the CNFL comb. The primary noise source is shown to be white amplitude noise on the oscillator pump laser combined with the sensitivity of the mode-locked laser to pump power fluctuations. The control bandwidth of f[subscipt]0 was limited by the response dynamics of the CNFL comb. The significant reduction of comb noise has been observed by implementing a phase-lead compensation to extend control bandwidth of the comb and by reducing the pump relative intensity noise simultaneously. Therefore the f[subscipt]0 linewidth has been narrower from 850 kHz to 220 kHz. The integrated phase noise for the f[subscipt]0 lock is 1.6 radians from 100 Hz to 102 kHz.

Optical Metrology for Precision Engineering

Optical Metrology for Precision Engineering
Author: Wei Gao
Publisher: Walter de Gruyter GmbH & Co KG
Total Pages: 655
Release: 2021-11-22
Genre: Technology & Engineering
ISBN: 3110542366

This book provides readers the fundamentals of optical metrology for precision engineering. The next-generation measurement technologies based on ultrashort pulse laser and optical frequency comb are also presented, making it an essential reference book for various engineering fields. • Introduces fundamental theories and techniques • Combines theories with practical applications • Presents technologies in an easy-to-understand way

Stabilization, Gate Control and Ultrafast Dynamics of Microresonator Optical Frequency Combs

Stabilization, Gate Control and Ultrafast Dynamics of Microresonator Optical Frequency Combs
Author: Abhinav Kumar Vinod
Publisher:
Total Pages: 155
Release: 2021
Genre:
ISBN:

An optical frequency comb (OFC) is a light source whose spectrum comprises of several sharp, equally spaced lines. They were originally developed more than two decades ago to simplify the measurement of optical frequencies in terms of precise atomic standards. OFC technology has progressed remarkably since the first demonstration and OFCs are now the cornerstones of modern-day frequency metrology, precision spectroscopy, astronomical observations, ultrafast optics and quantum information. While the current bulk mode-locked laser frequency comb has had great success in extending the scientific frontier, its use in real-world applications beyond the laboratory setting remains an unsolved challenge due to the relatively large size, weight and power consumption. Recently microresonator-based frequency combs have emerged as a candidate solution with chip-scale implementation and scalability. Microresonator platforms for comb generation are the subject of significant research efforts, which are primarily focused into three areas - comb stabilization, control over comb state generated and evolution paths and study of the comb formation dynamics. In this dissertation we focus on each of these three different areas. First, a novel internal phase-stabilized frequency microcomb that does not require nonlinear second-third harmonic generation nor optical external frequency references is demonstrated. It is shown that the optical frequency can be stabilized by control of two internally accessible parameters: an intrinsic comb offset and the comb spacing. Second, direct electrical control of microresonator parameters is achieved by coupling the gate-tunable optical conductivity of graphene to a silicon nitride photonic microresonator, and modulating its second- and higher-order chromatic dispersions by altering the Fermi level. This is then used to produce charge-tunable primary comb lines from 2.3 terahertz to 7.2 terahertz, coherent Kerr frequency combs, controllable Cherenkov radiation and controllable soliton states, all in a single microcavity. In addition, voltage-tunable transitions between soliton crystal states with defects with defects is demonstrated and mapped via ultrafast second-harmonic optical autocorrelation. Finally, novel ultrafast spectral and temporal measurement techniques are characterized and used to directly capture snapshots of the microresonator field at resolutions of less than 1 ps. These methods are applied to study spectral energy transfer, complex breathing dynamics, collective motion in soliton ensembles and the occurrence of extreme events from a chaotic background.

Nonlinear Photonics

Nonlinear Photonics
Author: Hyatt M. Gibbs
Publisher: Springer Science & Business Media
Total Pages: 218
Release: 2012-12-06
Genre: Science
ISBN: 3642754384

Nonlinear photonics is the name given to the use of nonlinear optical devices for the generation, communication, processing, or analysis of information. This book is a progress report on research into practical applications of such devices. At present, modulation, switching, routing, decision-making, and detection in photonic systems are all done with electronics and linear optoelectronic devices. However, this may soon change, as nonlinear optical devices, e.g. picosecond samplers and switches, begin to complement optoelectonic devices. The authors succinctly summarize past accomplishments in this field and point to hopes for the future, making this an ideal book for newcomers or seasoned researchers wanting to design and perfect nonlinear optical devices and to identify applications in photonic systems.

Sub-harmonic Generation of Frequency Combs for Spectroscopy and Quantum Optics

Sub-harmonic Generation of Frequency Combs for Spectroscopy and Quantum Optics
Author: Alireza Marandi
Publisher:
Total Pages:
Release: 2012
Genre:
ISBN:

Extensive development of optical frequency combs, broadband coherent light sources with equidistant narrow spectral lines, in the near-infrared and visible has provided numerous opportunities in many fields, including frequency metrology, astronomy, attosecond sciences, and spectroscopy. The quest for extension of frequency comb techniques to the mid-infrared -- the molecular fingerprint spectral region -- continues with the promise of significant improvements in various applications related to molecular spectroscopy. This dissertation presents the results of a novel method for producing broadband mid-infrared frequency combs through sub-harmonic generation from commercially available near-infrared sources. Sub-harmonic generation occurs in a degenerate optical parametric oscillator (OPO) with salient features of (i) simplicity of the setup, (ii) low (100 mW) pump power requirement, (iii) potential for high ( 90%) conversion eciency and (vi) intrinsic phase and frequency locking to the pump. The resulting mid-infrared frequency comb is then broadened through supercontinuum generation by in-situ tapering of a chalcogenide fiber to cover the spectral range from 2.2 to 5 microns, desirable for molecular spectroscopy. Apart from its effectiveness in extension of the existing near-infrared frequency combs to the mid-infrared, sub-harmonic generation paves the way for quantum optical experiments in the frequency comb regime, because of the intriguing quantum behavior of OPOs at degeneracy. The coherence properties of such a frequency comb OPO are discussed, and the results of a novel all-optical post-precessing-free quantum random number generator are presented.