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Related papers: Gapless dual-comb spectroscopy in terahertz region

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Terahertz single-pixel imaging (THz SPI) has garnered widespread attention for its potential to overcome challenges associated with THz focal plane arrays. However, the inherently long wavelength of THz waves limits imaging resolution,…

Image and Video Processing · Electrical Eng. & Systems 2025-08-05 Yongsheng Zhu , Shaojing Liu , Ximiao Wang , Runli Li , Haili Yang , Jiali Wang , Hongjia Zhu , Yanlin Ke , Ningsheng Xu , Huanjun Chen , Shaozhi Deng

High-resolution imaging in the terahertz (THz) spectral range remains fundamentally constrained by the limited numerical apertures of currently existing state-of-the-art imagers, which restricts its applicability across many fields, such as…

We present a temporally-multiplexed dual-colour terahertz (THz) imaging technique using THz-to-optical conversion in atomic vapour. By rapidly alternating the pump laser frequency, we sequentially excite two atomic states, each absorbing a…

Atomic Physics · Physics 2025-07-16 Lucy A. Downes , C. Stuart Adams , Kevin J. Weatherill

Dual-comb interferometry harnesses the interference of two laser frequency combs to provide unprecedented capability in spectroscopy applications. In the past decade, the state-of-the-art systems have reached a point where the…

Quantum Physics · Physics 2023-09-20 Haowei Shi , Zaijun Chen , Scott E. Fraser , Mengjie Yu , Zheshen Zhang , Quntao Zhuang

In the terahertz frequency range, the quantum cascade laser (QCL) is a suitable platform for the frequency comb and dual-comb operation. Improved comb performances have been always much in demand. In this work, by employing a symmetric…

Optics · Physics 2021-08-27 Chenjie Wang , Ziping Li , Xiaoyu Liao , Wen Guan , Xuhong Ma , Kang Zhou , J. C. Cao , Hua Li

Single cavity dual-comb fiber lasers adopting different multiplexing configurations are benefited from the natures of common-mode noise suppression and superior coherence. Particularly, repetition-rate tunable dual-combs enable…

Two frequency combs can be used to measure the full complex response of a sample in a configuration which can be alternatively viewed as the equivalent of a dispersive Fourier transform spectrometer, infrared time domain spectrometer, or a…

Optics · Physics 2015-05-18 I. Coddington , W. C. Swann , N. R. Newbury

In Terahertz (THz) technology, one of the long-standing challenges has been the formation of intense pulses covering the hard-to-access frequency range of 1-15 THz (so-called THz gap). This frequency band, lying between the electronically…

Optics · Physics 2014-07-29 C. Vicario , B. Monoszlai , M. Jazbinsek , S. -H Lee , O. -P. Kwon , C. P. Hauri

Terahertz (THz) communication (0.1-10 THz) is regarded as a promising technology, which provides rich available bandwidth and high data rate of terahertz bit per second (Tbps). However, THz signals suffer from high path loss, which…

Information Theory · Computer Science 2021-05-26 Sha Xie , Lingxiang Li , Zhi Chen , Shaoqian Li

Two techniques that employ equally spaced trains of optical pulses to map an optical high frequency into a low frequency modulation of the signal that can be detected in real time are compared. The development of phase-stable optical…

Quantum Physics · Physics 2017-08-22 Kochise Bennett , Jeremy Rouxel , Shaul Mukamel

Multiheterodyne techniques using frequency combs -- light sources whose lines are perfectly evenly-spaced -- have revolutionized optical science. By beating an unknown signal with the many lines of a comb, its spectrum is recovered.…

Optics · Physics 2020-04-23 David Burghoff

We perform dual-comb spectroscopy in two UV bands: 325-342 nm and 372-410 nm, corresponding to the 7th and 6th harmonics of a dual-comb 2.35-{\mu}m laser source, and simultaneously resolve ~500,000 and ~1,000,000 comb lines spaced by 80 MHz…

We describe a possible new technique for precise wavelength calibration of high-resolution astronomical spectrographs using femtosecond-pulsed mode-locked lasers controlled by stable oscillators such as atomic clocks. Such `frequency combs'…

Coherent detection and interferometry in the terahertz (THz) regime are key capabilities that enable applications ranging from astronomy to non-destructive testing. Phase-sensitive THz detection is currently achieved using nonlinear…

Optical frequency combs based on mode-locked lasers have proven to be invaluable tools for a wide range of applications in precision spectroscopy and metrology. A novel principle of optical frequency comb generation in whispering-gallery…

Optics · Physics 2015-06-12 Pascal Del'Haye , Scott B. Papp , Scott A. Diddams

We describe an electro-optic dual-comb system that operates in the near-infrared (near-IR) region to generate optical frequency combs in the near-UV by sum frequency generation in two configurations. The near-IR frequency combs are…

Optics · Physics 2024-11-08 Jasper R. Stroud , David F. Plusquellic

Optical rectification is demonstrated in (110)-cut ZnGeP_2 (ZGP) providing broadband terahertz (THz) generation. The source is compared to both GaP and GaAs over a wavelength range of 1150 nm to 1600 nm and peak intensity range of 0.5…

A four-wave-mixing, frequency-comb-based, hyperspectral imaging technique that is spectrally precise, potentially rapid, and can in principle be applied to any material, is demonstrated in a near-diffraction-limited microscopy application.

Optics · Physics 2021-07-21 Brad C. Smith , Bachana Lomsadze , Steven T. Cundiff

Electro-optic frequency combs with tooth spacings as low as 100 Hz were employed to probe electromagnetically induced transparency (EIT) and hyperfine pumping in rubidium and potassium vapor cells. From the potassium EIT transition we were…

Atomic Physics · Physics 2018-12-27 David A. Long , Adam J. Fleisher , Joseph T. Hodges

We present a terahertz time-domain spectroscopy (THz-TDS) system which accesses a broadband spectrum, efficiently covering the so-called "new THz gap" between 5 and 15 THz and extending beyond 25 THz. The system exploits nonlinear…