- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Surface-polaritonic phase singularities and multimode polaritonic frequency combs via dark rogue-wave excitation in hybrid plasmonic waveguide
摘要： Material characteristics and input-?eld speci?cs limit controllability of nonlinear electromagnetic-?eld interactions. As these nonlinear interactions could be exploited to create strongly localized bright and dark waves, such as nonlinear surface polaritons, ameliorating this limitation is important. We present our approach to amelioration, which is based on a surface-polaritonic waveguide recon?guration that enables excitation, propagation and coherent control of coupled dark rogue waves having orthogonal polarizations. Our control mechanism is achieved by ?nely tuning laser-?eld intensities and their respective detuning at the interface between the atomic medium and the metamaterial layer. In particular, we utilize controllable electromagnetically induced transparency windows commensurate with surface-polaritonic polarization-modulation instability to create symmetric and asymmetric polaritonic frequency combs associated with dark localized waves. Our method takes advantage of an atomic self-defocusing nonlinearity and dark rogue-wave propagation to obtain a suf?cient condition for generating phase singularities. Underpinning this method is our theory which incorporates dissipation and dispersion due to the atomic medium being coupled to nonlinear surface-polaritonic waves. Consequently, our waveguide con?guration acts as a bimodal polaritonic frequency-comb generator and high-speed phase rotator, thereby opening prospects for phase singularities in nanophotonic and quantum communication devices.
关键词： rogue wave,surface plasmon polariton,frequency comb,plasmonic waveguide,electromagnetically induced transparency
更新于2025-09-23 15:21:01
-
Quantum cascade laser based hybrid dual comb spectrometer
摘要： Four-wave-mixing-based quantum cascade laser frequency combs (QCL-FC) are a powerful photonic tool, driving a recent revolution in major molecular fingerprint regions, i.e. mid- and far-infrared domains. Their compact and frequency-agile design, together with their high optical power and spectral purity, promise to deliver an all-in-one source for the most challenging spectroscopic applications. Here, we demonstrate a metrological-grade hybrid dual comb spectrometer, combining the advantages of a THz QCL-FC with the accuracy and absolute frequency referencing provided by a free-standing, optically-rectified THz frequency comb. A proof-of-principle application to methanol molecular transitions is presented. The multi-heterodyne molecular spectra retrieved provide state-of-the-art results in line-center determination, achieving the same precision as currently available molecular databases. The devised setup provides a solid platform for a new generation of THz spectrometers, paving the way to more refined and sophisticated systems exploiting full phase control of QCL-FCs, or Doppler-free spectroscopic schemes.
关键词： frequency comb,spectroscopy,Quantum cascade laser,metrology,terahertz
更新于2025-09-23 15:21:01
-
Nonlinear Optics
摘要： The mid-infrared atmospheric window of 3–5.5 μm holds valuable information regarding molecular composition and function for fundamental and applied spectroscopy. Using a robust, mode-locked fiber-laser source of < 11 fs pulses in the near infrared, we explore quadratic (χe2T) nonlinear optical processes leading to frequency comb generation across this entire mid-infrared atmospheric window. With experiments and modeling, we demonstrate intrapulse difference frequency generation that yields few-cycle mid-infrared pulses in a single pass through periodically poled lithium niobate. Harmonic and cascaded χe2T nonlinearities further provide direct access to the carrier-envelope offset frequency of the near infrared driving pulse train. The high frequency stability of the mid-infrared frequency comb is exploited for spectroscopy of acetone and carbonyl sulfide with simultaneous bandwidths exceeding 11 THz and with spectral resolution as high as 0.003 cm?1. The combination of low noise and broad spectral coverage enables detection of trace gases with concentrations in the part-per-billion range.
关键词： few-cycle pulses,mid-infrared,frequency comb,spectroscopy,nonlinear optics
更新于2025-09-23 15:21:01
-
Frequency comb interference spectroscopy using a fiber laser comb and a multi-colour laser
摘要： In this paper, we demonstrate a rapid high-resolution frequency comb spectrometer involving a mode-locked laser comb and a multi-colour laser. The heterodyne detection of the two lasers enables hundreds of thousands of Doppler-limited molecular spectra to be recorded in a second. With this device, several P-branch transitions of the H13CN (gas) 2ν3-band are simultaneously interrogated at comb-line-defined resolution (54.5 MHz or 0.5 pm) within 3 μs. The single-measurement spectrum spans >200 GHz (~1.6 nm) far beyond the electronic bandwidth (33 GHz) of our acquisition system. Without using asynchronous combs or dispersers and detection arrays, the spectrometer may benefit many gas sensing applications, such as environmental monitoring.
关键词： frequency comb,fiber laser,spectroscopy
更新于2025-09-23 15:21:01
-
Tunable optical frequency comb from a compact and robust Er:fiber laser
摘要： We report on a compact and robust self-referenced optical frequency comb with a tunable repetition rate, generated by an all-polarization-maintaining (PM) mode-locked Er-doped fiber laser. The spacing between comb teeth can be tuned above 300 kHz at a repetition rate of 101 MHz. The repetition rate and the carrier–envelope offset of the laser are stabilized separately, and the relative residual phase noises are determined to be 336 μrad and 713 mrad (1 Hz–1 MHz). The accurate frequency characteristics and the stable structure show great potential for the use of such a comb in applications of precision measurements.
关键词： fiber laser,optical frequency comb,all-polarization-maintaining,mode-locking
更新于2025-09-23 15:21:01
-
Widely tunable ytterbium-doped single-frequency all-fiber laser
摘要： We demonstrate a widely tunable ytterbium-doped single frequency all-fiber laser with a computer-controlled tunable filter and a home-made comb spectrum filter. The comb filter is realized by fusing a single strand of polarization maintaining optical fiber into a double-circulator interferometer. The spectral performance of the comb filter is verified by theoretical and experimental studies. Wavelength-tunable single frequency operation in about 55 nm (1030–1085 nm) range can be achieved through the combined effect of these two filters. The experimental outcomes exhibit that an ultra-narrow linewidth of 435 Hz with high optical signal to noise ratio greater than 50 dB and high stability of operation wavelength and output power (0.016 nm and 0.38 dB, respectively) at room temperature. Our studies provide a new way to obtain the wide-range tunable single frequency fiber laser.
关键词： Wavelength-tunable,Fiber laser,Ultra-narrow linewidth,Single frequency,Comb spectrum filter
更新于2025-09-23 15:21:01
-
Robust, Synchronous Optical Buffer and Logic Operation in Dual-pump Kerr Micro-Resonator
摘要： Temporal cavity solitons (CSs) have been proposed to store the information in form of optical bits in a single-pump Kerr micro-resonator. However, such optical buffers (OBs) realized using a single-pump are essentially asynchronous in nature. In this paper, we show that dual-pump scheme can lead to both synchronous and robust OB. Numerical simulations reveal the resilience in the performance of the OB against the writing jitters and third-order dispersion induced temporal-drift. The impact of non-ideal operating conditions such as unequal pump amplitudes and pump detuning mismatch on the performance of the synchronous OB are evaluated and the robustness of the OB with respect to these aspects are explored both analytically and numerically. As an interesting application of the proposed dual-pump scheme, we have demonstrated the capability to perform simultaneous logic operations (AND, OR) of the proposed device. All the conclusions are supported by analytical and semi-analytical approaches.
关键词： Cavity Solitons,Kerr Frequency Comb,Optical Buffer,Dual pump
更新于2025-09-23 15:21:01
-
[IEEE 2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz2018) - Nagoya, Japan (2018.9.9-2018.9.14)] 2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Tuneable Optical Frequency Comb Generator for THz Spectroscopy
摘要： We present an optical frequency comb generator with a record span of 3.8 THz suitable for high resolution THz spectroscopy, based on a single phase modulator system. The line spacing, exactly referenced to a microwave synthesizer, can be continuously tuned from 17.5 GHz to 20 GHz overcoming the limitation otherwise imposed by the free spectral range of the fibre loop, making the system capable of generating a continuously tuneable electrical signal from 122.5 GHz to >2.7 THz. The system noise has been measured up to a record frequency of 300 GHz, and shown to be limited by the multiplied phase noise of the reference synthesizer.
关键词： THz spectroscopy,tuneable,heterodyne signal,phase modulator,optical frequency comb generator
更新于2025-09-23 15:21:01
-
Terahertz Spectroscopy of Gas Mixtures with Dual Quantum Cascade Laser Frequency Combs
摘要： Terahertz laser frequency combs based on quantum cascade lasers provide coherent, broadband, electrically pumped, THz radiation sources for use in future spectroscopic applications. Here, we explore the feasibility of such lasers in a dual-comb spectroscopy configuration for the detection of multiple molecular samples in the gas phase. The lasers span approximately 180 GHz of optical bandwidth, centered at 3.4 THz with sub-milliwatt total optical power. One of the main advantages of dual-comb spectroscopy is its high speed, which opens up the possibility for direct observations of chemical reaction dynamics in the terahertz spectral region. As a proof-of-concept, we recorded continuously evolving spectra from gas mixtures with 1 ms temporal resolution.
关键词： frequency comb,multi-species,Terahertz,real-time,dual-comb spectroscopy,quantum cascade laser
更新于2025-09-23 15:19:57
-
Laser optical frequency combs and their applications in optical fibre communication systems and astrophysics
摘要： This paper examines the generation and applications of laser optical frequency combs (LOFCs). The unique properties of LOFCs are widely used in spectroscopy and metrology, in particular for making ultra-accurate optical clocks. The use of LOFCs contributes to advances in optical fibre communication systems and studies pertaining to fundamental problems of astrophysics, such as the search for and investigation of exoplanets and verification of the hypothesis that physical constants vary with time.
关键词： exoplanets,optical frequency comb,calibration of astronomical spectrographs,multiplexing,Doppler spectroscopy
更新于2025-09-23 15:19:57