Pulse-on-demand laser operation from nanosecond to femtosecond pulses and its application for high-speed processing

Abstract In this manuscript we present a true pulse-on-demand laser design concept using two different approaches. First, we present a fiber master oscillator power amplifier (MOPA) based quasi-continuous wave (CW) laser, working at high modulation bandwidths, for generation of nanosecond pulses. Second, we present a hybrid chirped pulse amplification (CPA)-based laser, combining a chirped-pulse fiber amplifier and an additional solid-state amplifier, for generation of femtosecond pulses. The pulse-on-demand operation is achieved without an external optical modulator/shutter at high-average powers and flexible repetition rates up to 40 MHz, using two variants of the approach for near-constant gain in the amplifier chain. The idler and marker seed sources are combined in the amplifier stages and separated at the out using either wavelength-based separation or second harmonic generation (SHG)-generation-based separation. The nanosecond laser source is further applied to high throughput processing of thin film materials. The laser is combined with a resonant scanner, using the intrinsic pulse-on-demand operation to compensate the scanner’s sinusoidal movement. We applied the setup to processing of indium tin oxide (ITO) and metallic films on flexible substrates.

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Лазерно-индуцированный графен на полиимидной пленке: наблюдение эффекта увлечения

Письма в журнал технической физики ◽

10.21883/pjtf.2020.09.49375.18152 ◽

2020 ◽

Vol 46 (9) ◽

pp. 51

Author(s):

К.Г. Михеев ◽

Р.Г. Зонов ◽

Д.Л. Булатов ◽

А.Е. Фатеев ◽

Г.М. Михеев

Keyword(s):

Continuous Wave ◽

Graphene Film ◽

Laser Pulses ◽

Wavelength Dependence ◽

Polyimide Film ◽

Film Structure ◽

Laser Generation ◽

Nanosecond Laser ◽

Nanosecond Pulses ◽

Wide Range

Porous graphene film structures were produced by irradiation of polyimide film with focused continuous wave CO2 laser. Generation of nanosecond pulses of photocurrent was observed in the obtained structures upon excitation by nanosecond laser pulses in a wide range of wavelengths. It is shown that the photocurrent linearly increases with pulsed laser power and its dependence on the angle of light incidence on the film structure is symmetric about the origin. Wavelength dependence of light-to-photocurrent conversion coefficient was measured. The obtained results are explained by photon-drag effect photocurrent generation.

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Hydrogen Sulfide Detection in the Midinfrared Using a 3D-Printed Resonant Gas Cell

Journal of Sensors ◽

10.1155/2019/6437431 ◽

2019 ◽

Vol 2019 ◽

pp. 1-7 ◽

Cited By ~ 3

Author(s):

Oscar E. Bonilla-Manrique ◽

Harald Moser ◽

Pedro Martín-Mateos ◽

Bernhard Lendl ◽

Marta Ruiz-Llata

Keyword(s):

Hydrogen Sulfide ◽

Continuous Wave ◽

Limit Of Detection ◽

Second Harmonic ◽

External Cavity ◽

Gas Absorption ◽

Laser Source ◽

Beam Power ◽

Absorption Data ◽

3D Printed

A fast and reliable photoacoustic (PA) sensor for trace gas detection is reported. The sensor is based on a 3D-printed resonant cell in combination with a continuous wave mode-hop-free external cavity quantum cascade laser to rapidly acquire gas absorption data in the midinfrared range. The cell is designed so as to minimize the window PA background at a selected acoustic resonance. The goal is a resonant PA cell capable of detecting the traces of gases using wavelength modulation of the laser source and second harmonic detection. The versatility and enhancement of the limit of detection at sub-ppm levels are investigated by monitoring specific lines of hydrogen sulfide (H2S). The noise-equivalent absorption normalized to laser-beam power and detection bandwidth is 1.07×10-8 W cm-1 Hz-1/2 for H2S targeting the absorption line at 1247.2 cm−1. These properties make the sensor suitable for various practical sensors for water quality applications.

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High average power femtosecond pulses at 520 nm via second harmonic generation of a fiber chirped pulse amplification system

Advances in Optical Materials ◽

10.1364/filas.2011.fthb2 ◽

2011 ◽

Author(s):

T. Eidam ◽

S. Hädrich ◽

J. Rothhardt ◽

F. Stutzki ◽

F. Jansen ◽

...

Keyword(s):

Second Harmonic Generation ◽

Harmonic Generation ◽

Second Harmonic ◽

Average Power ◽

Femtosecond Pulses ◽

High Average Power ◽

Chirped Pulse ◽

Pulse Amplification ◽

Amplification System ◽

Chirped Pulse Amplification

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A High Speed and Ultra Long-Haul Radio-Over-Fiber System Employing Dual Photoelectric Arms Coherent Modulation and Optical Duo-Binary Coding

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.988.544 ◽

2014 ◽

Vol 988 ◽

pp. 544-547

Author(s):

Guang Li

Keyword(s):

High Speed ◽

Continuous Wave ◽

Single Mode ◽

Fiber Amplifier ◽

Radio Over Fiber ◽

Laser Source ◽

Signal Spectrum ◽

Fiber System ◽

Binary Coding ◽

Coherent Modulation

A novel high speed and ultra long-haul radio-over-fiber (ROF) system based on Dual Photoelectric Arms Coherent Modulation (DPACM) and Optical Duo-Binary Coding (ODBC) is proposed, and demonstrated. The signal spectrum bandwidth, generated by ODBC based on the first order DPACM, is half of non-return-to-zero (NRZ ) signal spectrum bandwidth. The secondary order DPACM generates a 40-GHz Millimeter-wave (mm-wave) that is transmitted over fiber (ROF). The simulation results show that, the bit rate can be up to 40 Gbps and the transmission distance is over 1500 Km, based on the ROF system with a 0 dBm continuous-wave laser source, multiple stages Er-Doped Fiber Amplifier (EDFA), a standard single mode fiber (SSMF) with a dispersion of 17 ps/nm/Km and a attenuation of 0.2 dB/Km.

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An Optical Frequency Domain Angle Measurement Method Based on Second Harmonic Generation

Sensors ◽

10.3390/s21020670 ◽

2021 ◽

Vol 21 (2) ◽

pp. 670

Author(s):

Wijayanti Dwi Astuti ◽

Hiraku Matsukuma ◽

Masaru Nakao ◽

Kuangyi Li ◽

Yuki Shimizu ◽

...

Keyword(s):

Femtosecond Laser ◽

Second Harmonic Generation ◽

Frequency Domain ◽

Harmonic Generation ◽

Measurement Method ◽

Second Harmonic ◽

Angle Measurement ◽

Laser Source ◽

Optical Frequency ◽

Measurable Range

This paper proposes a new optical angle measurement method in the optical frequency domain based on second harmonic generation with a mode-locked femtosecond laser source by making use of the unique characteristic of the high peak power and wide spectral range of the femtosecond laser pulses. To get a wide measurable range of angle measurement, a theoretical calculation for several nonlinear optical crystals is performed. As a result, LiNbO3 crystal is employed in the proposed method. In the experiment, the validity of the use of a parabolic mirror is also demonstrated, where the chromatic aberration of the focusing beam caused the localization of second harmonic generation in our previous research. Moreover, an experimental demonstration is also carried out for the proposed angle measurement method. The measurable range of 10,000 arc-seconds is achieved.

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Spectral Broadening in a Continuously Pumped Singly Resonant Second-Harmonic Cavity

Applied Sciences ◽

10.3390/app11157122 ◽

2021 ◽

Vol 11 (15) ◽

pp. 7122

Author(s):

Simona Mosca ◽

Tobias Hansson ◽

Maria Parisi

Keyword(s):

Continuous Wave ◽

Frequency Comb ◽

Second Harmonic ◽

Input Power ◽

Second Order ◽

Optical Frequency ◽

Frequency Combs ◽

Research Areas ◽

Mixed Regime ◽

Wide Range

Optical frequency comb synthesizers with a wide spectral range are an essential tool for many research areas such as spectroscopy, precision metrology, optical communication, and sensing. Recent studies have demonstrated the direct generation of frequency combs, via second-order processes, that are centered on two different spectral regions separated by an octave. Here, we present the capability of optical quadratic frequency combs for broad-bandwidth spectral emission in unexplored regimes. We consider comb formation under phase-matched conditions in a continuous-wave pumped singly resonant second-harmonic cavity, with large intracavity power and control of the detuning over several cavity line widths. The spectral analysis reveals quite distinctive sidebands that arise far away from the pump, singularly or in a mixed regime together with narrowband frequency combs. Notably, by increasing the input power, the optical frequency lines evolve into widely spaced frequency clusters, and at maximum power, they appear in a wavelength range spanning up to 100 nm. The obtained results demonstrate the power of second-order nonlinearities for direct comb production within a wide range of pump wavelengths.

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