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Overview of the development of optical frequency comb sources as function of year. The left axis indicates the mode-spacing of the various sources. To the right of the graph we indicate what mode-spacing range is most suitable for various applications. Milestones in source development, as well as some notable applications, beyond and including some of those listed in section "The offset frequency and measurement of the comb parameters", are indicated at the bottom and top of the graph. Filled markers indicate systems that have accessed f 0 , while empty markers have not. Sources that have become commercial products are circled with a solid outline and comb-based products are circled with a dashed outline and filled in yellow. AOWG -arbitrary optical waveform generation, OFD -optical frequency division, TWOTFT -two-way optical time and frequency transfer, DCS -dual-comb spectroscopy. List of references: 1 21,25,26 : 2 13 : 3 35 : 4 157 : 5 158-160 : 6 161 : 7 33,147 : 8 162 : 9 14 : 10 127 : 11 163 : 12 38 : 13 131 : 14 164 : 15 44 : 16 92 : 17 64 : 18 11 : 19 153 : 20 165 : 21 40 : 22 59 : 23 68 : 24 154 : 25 83 : 26 74 : 27 166 : 28 167 : 29 60 : 30 168 .
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Optical frequency combs were developed nearly two decades ago to support the world’s most precise atomic clocks. Acting as precision optical synthesizers, frequency combs enable the precise transfer of phase and frequency information from a high-stability reference to hundreds of thousands of tones in the optical domain. This versatility, coupled w...
Context in source publication
Context 1
... from 80 MHz, 2-m long Ti:sapphire laser systems to gigahertz repetition rate, directly octave spanning Ti:sapphire OFCs, to highly environmentally stable, all-polarization maintaining, fully fiberized compact Er:fiber OFCs 39 , and finally to monolithic, high-performance, sub-100 fs Er/Yb:glass lasers that can fit in the palm of one hand 59 , see Fig. ...
Similar publications
We present a detailed frequency noise analysis of a feedforward scheme used to faithfully transfer the spectral properties of an individual line of an optical frequency comb spectrum to a single-mode laser and in this way indirectly amplify it, which is applicable to any arbitrary comb mode spacing. In contrast to previously reported implementation...
Citations
... Another less explored application of OMOs is the generation of optical frequency combs (OFCs). Nowadays, extensive research is being conducted on OFCs due to their crucial role in various applications such as optical metrology, precision spectroscopy, optical clocks, and rf photonics [34][35][36]. So far, researchers have successfully utilized electro-optic (EO) modulation or intrinsic parametric nonlinearities of materials (such as Kerr media), commonly exhibiting high repetition rates, to demonstrate the integrated optical microcombs [36][37][38][39][40]. On the other hand, OFCs with low repetition rates (typically below 1 GHz) are better suited for other applications, such as high-resolution spectroscopy [41,42], mode-locked lasers with ultranarrow spectral widths [43], integrated pulse sources for quantum optics [44], and lownoise microwave frequency comb generations [45,46]. ...
Cavity optomechanical oscillations (OMOs) have been extensively studied for their rich physics and various practical applications. However, due to the highly nonlinear nature of the dynamical process, the exact sideband structure of an optomechanically oscillating optical cavity field remains unknown, although it is essential to a comprehensive understanding and accurate manipulation of such systems. Here, we establish a correspondence between the Bloch-band structure and the coupled sideband dynamics of OMOs, thus providing a theoretical framework for unveiling the detailed structure of cavity optical modes in terms of their resemblance to the well-known Wannier-Stark states and ladders. Surprisingly, the locations of these ladders are irrelevant to pump frequency or power but only depend on the resonant frequency of the optical mode and mechanical-mode frequency. By an energy transfer picture, we build up a connection between the highly nonlinear OMOs and a Bloch-band structure that can be solved linearly. Quantitatively, this picture uncovers the underlying mechanism of the optimization of the pump detuning and optical decay rate, as well as the determination of the minimum input pump power, for sustaining a cavity OMO.
Published by the American Physical Society 2025
... Frequency combs can be generated using various methods, including four-wave mixing in nonlinear media, periodic modulation of a continuous-wave laser, or stabilizing the pulse train generated by a mode-locked laser (Fortier and Baumann 2019). One advantage of utilizing four-wave mixing (FWM) for frequency comb generation is its transparent handling of data formats and bit rates. ...
This study introduces a waveguide design capable of generating supercontinuum spectrum and frequency combs within the mid-infrared range. The proposed structure consists of an As2Se3 core and cladding layers of MgF2 and SiO2, exhibiting two zero-dispersion wavelengths at 2100 nm and 2850 nm. Theoretical modeling and numerical simulations demonstrate the generation of a supercontinuum spanning a wavelength range of 4500 nm, from 1000 to 5500 nm, at a − 30 dB level, as well as frequency combs featuring up to 44 comb lines with a flatness of 15 dBm. The supercontinuum was generated in the maximum range of 30 dB using a 1 kW input pulse and 1 and 4 mm long waveguides. The generated frequency combs cover the wavelength range of 2073.1–2159.8 nm, making them suitable for applications such as gas sensing, industrial process monitoring, and medical diagnostics. The proposed waveguide design offers advantages over existing methods in terms of the number of comb lines, flatness, and effective area while operating in the mid-infrared region.
... Optical frequency combs and their discrete spectra enable phase-coherent links across the electromagnetic spectrum and underpin some of the most advanced measurements in physics [1,2]. Usually, they are derived from femtosecond pulsed lasers and their frequency components are described by ν m = mf rep + f ceo , where f rep and f ceo are the laser's pulse repetition rate and carrier-envelope-offset frequency, and m ∈ N 0 is the comb line index. ...
Optical frequency combs and their spectra of evenly spaced discrete laser lines are essential to modern time and frequency metrology. Recent advances in integrated photonic waveguides enable efficient nonlinear broadening of an initially narrowband frequency comb to multi-octave bandwidth. Here, we study the nonlinear dynamics in the generation of such ultra-broadband spectra where different harmonics of the comb can overlap. We show that a set of interleaved combs with different offset frequencies extending across the entire spectrum can emerge, which transform into a single evenly spaced ultra-broadband frequency comb when the initial comb is offset-free.
... Optical frequency combs have been utilized for over twenty years as a means of efficiently extracting information across a wide spectral bandwidth from optical systems [1]. The equidistant modes or 'teeth' for a comb allow it to perform single shot measurements of spectral features in the optical domain, which includes application to molecular absorption spectroscopy [2][3][4] and trace gas sensing [5][6][7]. ...
We present an acousto-optic frequency comb readout scheme synthesized from multiple intra-comb beat measurements using digitally enhanced heterodyne interferometry. The readout scheme enables a single acousto-optic frequency comb to achieve a compression factor, which normally requires a dual comb measurement scheme. We demonstrate an absorption measurement of the 2ν3 P10 line obtaining a noise equivalent absorption sensitivity of 1.75 × 10⁻⁸cm⁻¹Hz−1/2. Additionally we demonstrate the ability of the system to software-adjust the compression factor to access a wider optical bandwidth.
... In the optical realm, optical parametric coupling has played a major role in quantum engineering endeavors. [11][12][13][14][15][16][17] Optical frequency combs (FCs), 18,19 squeezed laser, 20 and squeezed optical frequency combs 13 have gained recognition as formidable tools for precision metrology and spectroscopy, positioning themselves as strong contenders for quantum processing. [21][22][23][24] The landscape of frequency comb (FC) research has seen a rich tapestry of studies delving into nonlinear processes, unveiling techniques for generating bosonic FCs. ...
We present a theoretical framework for generating squeezed microwave and magnonic frequency combs achieved through the parametric coupling of magnon modes to a cavity. This coupling exploits the intrinsic non-linear magnon modes of a ferromagnetic sphere. When subjected to a strong, coherent microwave field, we show that the system exhibits spontaneous generation of squeezed frequency combs. Our exploration crosses various regimes of comb generation, prominently highlighting phenomena such as squeezing and squeezed lasing. This study paves the way for a pioneering room-temperature, multi-frequency maser characterized by both its magnonic and microwave squeezing properties. The implications of our findings hold promise for advancements in spintronics, quantum sensing, information processing, and quantum networking.
... Since their groundbreaking realization in 2000 [1], optical frequency combs (OFCs) have demonstrated significant potential in various applications [2], including precision frequency measurement [3,4], time-frequency transfer [5][6][7][8], and optical frequency conversion [9,10]. These applications exploit the distinctive comb-like spectral properties of OFC, where each radio frequency (RF) or optical spectral line follows the formula f n = f ceo ± nf r ± f beat (with n being the comb tooth order, f ceo the carrier-envelope offset frequency, f r the repetition frequency, and f beat the beat frequency) [11,12]. ...
This paper presents a combined theoretical and experimental method for noise suppression in the repetition frequency (fr) locking of erbium-doped fiber optical frequency combs (OFCs). This study proposed a novel mathematical model to bridge the noise relationship of fr between the free-running and locked modes, and analyzed this relationship from two perspectives: the additional phase noise and the frequency stability. In addition, to integrate theoretical modeling with experimental validation, this study designed fr locking strategy that uses a phase-locked loop (PLL) with PFD + PIID (a phase frequency detector and a proportional, first-order integer, second-order integer, first-order differential controller). Under synchronization of the fr with a microwave reference (REF), this study achieved OFC additional frequency stabilities of 2.81 × 10−15@1 s and 8.08 × 10−19@10,000 s at 200 MHz fundamental frequency locking and 4.25 × 10−16@1 s and 1.91 × 10−19@10,000 s at 1200 MHz harmonic locking. The simulated and experimental results are in good agreement, confirming the consistency of the theoretical model and experiment. This work provides a reliable theoretical model that can be used to predict stability for OFC locking and significantly improves the additional frequency stability of OFCs.
... 7 Additionally, optical frequency comb technology continuously evolves for more than two decades and gains great interest for use in laser ranging, calibration of astronomical spectrographs, and comb-based spectroscopy. 8,9 For many of the above applications, the synchronized operation between different sources is essential, 10,11 and for this reason, much research effort has been devoted to the generation and control of synchronized pulse trains from different sources as well as to the phase locking of frequency combs using active and passive techniques or their combination. 11 Furthermore, coherent combining of phase locked lasers has been established as a method to address the limitations of the low optical power levels of single sources. ...
Two monolithic edge-emitting passively mode-locked InAs/InGaAs semiconductor quantum dot lasers generating ps optical pulses at repetition rates of 10 GHz and optical frequency combs centered at 1260 nm are mutually coupled in an all-optical passive synchronization experiment. The two lasers, with different free-running repetition rates, are coupled through a long delay fiber path, they synchronize, and generate optical pulse trains with identical repetition rates in a wide range of experimental conditions (optical frequency, optical delay, and coupling strength). The common repetition rate can be easily fine-tuned with the control of the external coupling path length. In synchronized state, both lasers operate with significantly reduced timing jitter with respect to their free-running values. Finally, under specific conditions, the repetition rate locking is accompanied by partial mutual coherence between the lasers, as indicated by the formation of interferometric fringes.
... An optical frequency comb, characterized by a series of equally spaced discrete lines, finds broad application in various fields [1][2][3]. The ability to accurately control the photonic sideband emission and process frequencyencoded quantum entanglement via one channel is at the heart of numerous quantum information applications, including universal one-way quantum computing [4,5], scalable generation of entangled cluster states [6,7] and high-dimensional entanglement protocols [8][9][10] in optical frequency comb. ...
... The radiative loss is characterized by the radiative decay rate γ 1D of an individual coupled emitter. To give rise to a frequency comb equally spaced by Ω in the scattered light spectrum, we impose a dynamical modulation on the resonance frequency of n th qubit with a general form ω n (t) = ω 0 + ∆ n (t) = ω 0 + R r=1 A n r cos(rΩt + α n r ), (1) where ω 0 is the equilibrium qubit resonance frequency; A n r and α n r are n-dependent amplitude and phase for r th modulation tone, respectively. Here, n enumerates the qubits that are spaced periodically, and the total number of the considered modulation tones is assumed to be R. ...
The capability to design spectrally controlled photon emission is not only fundamentally interesting for understanding frequency-encoded light-matter interactions, but also is essential for realizing the preparation and manipulation of quantum states. Here we consider a dynamically modulated qubit array, and realize frequency-controlled single-photon emission focusing on the generation of a frequency comb constituted solely of even-parity or anti-Stokes sidebands. Our system also offers parity-dependent bunching and antibunching in frequency-filtered quantum correlations. In particular, the waveguide quantum electrodynamics (QED) setup is extended to include chiral and non-local coupling architectures, thereby enhancing its versatility in Floquet engineering. Our proposal also supports the predictable generation of high-dimensional entangled quantum states, where the corresponding effective Hilbert space dimension is well controlled by energy modulation. Moreover, the utilisation of sophisticated numerical tools, such as the matrix product states (MPSs) and the discretization approach, enables the efficient simulation of multi-photon dynamics, in which the non-Markovian Floquet steady states emerge. This work fundamentally broadens the fields of collective emission, and has wide applications in implementing frequency-encoded quantum information processing and many-body quantum simulation.
... Both benefited each other with their respective technological advancements. In a parallel scientific universe, from 2000, the development of femtosecond lasers or optical frequency comb [4][5][6] has revolutionized the impact of RF-photonics in the field of high precision spectroscopy [7], arbitrary waveform generation [8], highly precise atomic clocks [9], arbitrary RF waveform generation [10] and massively parallel optical communication system [11][12][13][14][15][16][17][18][19][20][21]. An optical frequency comb is an optical range spectrum of multiple evenly spaced optical frequencies. ...
... A widely spaced and flat optical frequency comb with other required parameters discussed in section 2 can be exploited as a multichannel source for future flexible optical networks. To date, multiple approaches have been proposed to realize a comb-based WDM transmission system [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. The basic block diagram corresponding to the comb-based WDM transmission system is shown in figure 17. ...
A flexible optical communication network is needed to realize a backbone transport network for 6G communication and further higher generation communication technologies. However, the practical implementation of the higher generation network experiences some serious challenges due to the existing multicarrier generation technology i.e. an array of multiple discrete laser sources (less spectrally efficient, complex, bulkier and costlier). Recently, a multicarrier generation technique using the optical frequency comb has been extensively researched. It can reduce the complexity, cost, and size compared to the existing multicarrier generator. Moreover, it increases the utilization of available spectral efficiency due to its capability to tune the operating frequency and carrier spacing. So, considering these advantages, we reviewed the multiple optical frequency comb generation techniques, categorized as mode-locked laser, microresonator and electro-optic modulator based frequency combs. We identify the salient features of different frequency comb generation techniques by keeping the requirements of a flexible optical network in mind. We also reviewed the drawbacks and possible solutions proposed to improve the characteristics of the optical frequency comb. Further, we reviewed the optical frequency comb expansion techniques to broaden the spectrum of the optical frequency comb, which is the requirement in optical frequency comb suitable for communication applications. At last, we summarize the progress in the practical implementation of the optical frequency comb as a multichannel source in a flexible optical network.
... We employ electro-optic (EO) combs for the dual-comb heterodyne mixing scheme. Among the various techniques for frequency comb generation [26,27], EO combs stand out for their exceptionally flat spectral profile and the capability to adjust the repetition rate with great flexibility, making them ideal for frequency-diverse array applications [28,29]. A continuous-wave (CW) laser serves as the seed light which is split into two distinct paths -the signal path and the LO path -to create dual EO combs. ...
Phased array antennas (PAAs) possessing broadband beamforming capabilities are crucial for advanced radar and wireless communication systems. Nevertheless, traditional phase-shifter-based PAA beamformers frequently encounter the beam-squint issue, which substantially restricts their instantaneous bandwidth. Photonic true-time-delay (TTD) beamformers have the potential to overcome this challenge, offering ultrawide bandwidth and immunity to electromagnetic interference. However, their practical application is impeded by the high complexity, which typically involves a vast array of optical switches and delay lines. Here, we introduce a novel frequency-comb-steered photonic quasi-TTD beamformer that eliminates the need for delay lines by leveraging the concepts of frequency-diverse arrays and photonic microwave mixing arrays. This beamformer enables squint-free beamforming of ultrawideband linear frequency modulation waveforms, which is essential for high-resolution radar applications. It ensures seamless and continuous beam steering, effectively delivering infinite spatial resolution. We present a prototype with an 8-element PAA, demonstrating an instantaneous bandwidth of 6 GHz across the entire Ku-band. Additionally, we explore the system's capabilities in integrated inverse synthetic aperture radar imaging and high-speed communication, achieving a high imaging resolution of 2.6 cm * 3.0 cm and a transmission rate of 3 Gbps. Compared to conventional delay-line-based beamformers, our new concept markedly reduces hardware complexity and enhances scalability, positioning it as a potent enabler for future integrated sensing and communication applications.
