Pulsed electro-optic modulation for efficient, active continuous-wave laser mode-locking

We demonstrated efficient active mode-locking of a Nd:YAG laser using broad bandwidth, pulsed electro-optic modulation. A 10 GHz, LiTaO3 traveling wave phase modulator, driven by 300 ps FWHM electrical pulses with less than 1 mW of drive power, was used to generate detector-limited, mode-locked laser pulses of less than 50 ps duration at 76 MHz. Shorter modulator drive pulses are possible and near bandwidth-limited mode-locked pulses should be attainable. The use of pulsed modulation rather than conventional sinusoidal modulation permits both pulse width and pulse build-up time reductions and generally makes active mode-locking competitive with passive mode-locking for relatively low-gain and narrow-bandwidth lasers.

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Generation of flat power-envelope terahertz-wide modulation sidebands from a continuous-wave laser based on an external electro-optic phase modulator

Optics Letters ◽

10.1364/ol.30.000777 ◽

2005 ◽

Vol 30 (7) ◽

pp. 777 ◽

Cited By ~ 20

Author(s):

Shintaro Hisatake ◽

Yuko Nakase ◽

Kyoji Shibuya ◽

Tetsuro Kobayashi

Keyword(s):

Continuous Wave ◽

Phase Modulator ◽

Continuous Wave Laser ◽

Electro Optic ◽

Wave Laser

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Temperature Field of Repetitive Laser Pulse Irradiation and its Effect on Laser Surface Hardening

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.110-116.823 ◽

2011 ◽

Vol 110-116 ◽

pp. 823-830 ◽

Cited By ~ 1

Author(s):

Aniruddha Gupta ◽

Ashish Kumar Nath

Keyword(s):

Laser Pulse ◽

Surface Hardening ◽

Continuous Wave ◽

High Carbon Steel ◽

Laser Pulses ◽

Phase Transformation Temperature ◽

Continuous Wave Laser ◽

Pulse Irradiation ◽

Soaking Time ◽

Analytical Expressions

Analytical expressions for the temperature rise in a semi-infinite workpiece due to the heating with CW and repetitive laser pulse irradiation have been derived. It has been shown that the soaking time at a temperature above the phase transformation temperature, on which the homogeneity of microstructure and the depth of hardening depend, can be increased by heating with repetitive laser pulses. Experimental results of surface hardening of high-carbon steel with repetitive laser pulses showed higher depth of hardening and better microstructure homogeneity compared to those with continuous wave laser.

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Ultrafast electro-optic light with subcycle control

Science ◽

10.1126/science.aat6451 ◽

2018 ◽

Vol 361 (6409) ◽

pp. 1358-1363 ◽

Cited By ~ 43

Author(s):

David R. Carlson ◽

Daniel D. Hickstein ◽

Wei Zhang ◽

Andrew J. Metcalf ◽

Franklyn Quinlan ◽

...

Keyword(s):

High Speed ◽

Near Infrared ◽

Continuous Wave ◽

Mode Locking ◽

Light Sources ◽

Electro Optic ◽

High Pulse ◽

Optical Cycle ◽

Rapid Transients ◽

And Control

Light sources that are ultrafast and ultrastable enable applications like timing with subfemtosecond precision and control of quantum and classical systems. Mode-locked lasers have often given access to this regime, by using their high pulse energies. We demonstrate an adaptable method for ultrastable control of low-energy femtosecond pulses based on common electro-optic modulation of a continuous-wave laser light source. We show that we can obtain 100-picojoule pulse trains at rates up to 30 gigahertz and demonstrate sub–optical cycle timing precision and useful output spectra spanning the near infrared. Our source enters the few-cycle ultrafast regime without mode locking, and its high speed provides access to nonlinear measurements and rapid transients.

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