Here, we report the rotational stimulated Raman scattering (SRS) of hydrogen molecules in an all-fiber cavity based on hollow-core photonic crystal fibers (HC-PCFs). The gas cavity consists of a 49 m ...long HC-PCF filled with 18 bar high-pressure hydrogen and two sections of fusion spliced solid-core fibers on both ends. When pumped by a homemade 1064 nm pulsed fiber amplifier, only rotational SRS occurs in the gas cavity due to the transmission spectral characteristics of the used HC-PCF, and 1135 nm Stokes wave is obtained (Raman frequency shift of 587 cm−1). By changing the pulse width and repetition frequency of the pump source, the output characteristics are explored. In addition, a theoretical model is established for comparison with the experimental results. This work is helpful for the application of gas Raman laser based on the HC-PCFs.
This paper presents a comprehensive study of the design and parametric investigation of a diode pump alkali laser (DPAL): an emerging, high quantum efficiency, challenging laser system in the ...near-infrared region with potential for numerous applications. It covers the design and development of a diode pumped alkali (rubidium) laser (Rb:DPAL) gain cell and associated subsystems including the glove box-based alkali transfer set-up. Laser generation (
λ
∼
795
nm
) in a continuous wave (CW) mode with end-pumped geometry in the Rb cell is reported. Comparative studies on the Rb-DPAL output were carried out with various critical operating parameters such as buffer gas pressure, buffer gas composition, gain medium temperature and pump power / intensity. The experimental results were analysed and discussed in light of the efficacy of the pump beam absorption, the laser level kinetics and effective lasing volume in the Rb-DPAL gain cell.
The results of experimental studies of the surface roughness and the microstructure of high-speed steel R6M5 after gas-laser cutting are presented. It is shown that the parameters the surface ...roughness obtained in the case of the studied samples correspond to typical values of the surface-roughness parameters after such types of machining as turning or grinding operations. In the course of gas-laser cutting, a quenching zone up to 110 μm in depth with an increased microhardness amounting to 10 600 ± 160 MPa is formed in the surface layer. Short-term tempering in the temperature range of A
c1
–620°С does not lead to decomposition of the martensite; neither a transition zone nor tempering zone are revealed.
A 3D continuous-wave (CW) terahertz computed tomography (CT) system employing a gas laser operating at 2.52 THz is presented. To shorten acquisition time on the premise of guaranteeing the image ...quality, the modified simultaneous algebraic reconstruction technique (MSART) coupled with image processing operations like the Gaussian low-pass filter (GLPF), open operation and close operation has been adopted in the paper. With the 2D results the 3D images of the samples have been also obtained. The reconstruction results illustrate the promising application prospects of this CW THz CT system.
A stable external cavity diode laser coupled with volume Bragg grating for metastable argon atoms pumping is presented. The measured maximum output power of the continuous wave is 6.5W when the ...spectral width (FWHM) is less than 21pm around 811.53nm and the power efficiency is 68%. The tuning range of the emission wavelength is bigger than 270pm. The calculated deviation in relative absorption efficiency caused by the fluctuations of wavelength and power is less than 4%.
•Diode laser with spectral width less than 21pm for Ar* pumping is presented.•The laser performs good long-term stabilities in wavelength and power.•Influence of wavelength deviation on relative absorption efficiency is calculated.
The influence of zinc additives on the copper vapor laser output characteristics has been studied. On the basis of summarizing the results of the various types of metal additives action an assumption ...on a single mechanism of influence has been suggested and justified being related to the correction of thermal physical parameters of laser.
Development of safe infrared gas lasers Mainuddin; Singhal, Gaurav; Tyagi, R.K. ...
Optics and laser technology,
April 2013, 2013-4-00, Letnik:
47
Journal Article
Recenzirano
Infrared gas lasers find application in numerous civil and military areas. Such lasers are therefore being developed at different institutions around the world. However, the development of chemical ...infrared gas lasers such as chemical oxygen iodine lasers (COIL) involves the use of several hazardous chemicals. In order to exploit full potential of these lasers, one must take diligent care of the safety issues associated with the handling of these chemicals and the involved processes. The present paper discusses the safety aspects to be taken into account in the development of these infrared gas lasers including various detection sensors working in conjunction with a customized data acquisition system loaded with safety interlocks for safe operation. The developed safety schemes may also be implemented for CO2 gas dynamic laser (GDL) and hydrogen fluoride–deuterium fluoride (HF–DF) Laser.
► This paper discusses the safety aspects and detection schemes for infrared gas lasers. ► Safety schemes for infrared gas lasers in general and COIL in particular have been implemented. ► For COIL system, chlorine, iodine and BHP and others safety have been implemented. ► An emergency situation has been deliberately created to test the developed system. ► The safety aspect of HF–DF and CO2 GDL and their possible detection units have been discussed.
A compact and efficient mirror-less cavity is presented for an optically pumped 192-μm far-infrared laser. With a gold-coated mirror and 30°-inclined anti-reflection coated Ge plate serving as highly ...reflective mirrors, a folded mirror-less CH
3
F cavity is achieved. Maximum energy of 0.72 mJ is obtained with the pump energy of 600 mJ, which gives an energy increment of 75% in comparison with the previous 1.85-m mirror-less system. The beam divergence angle of the FIR radiation from this folded mirror-less cavity is measured to be 14.2 mrad.
The frequency of four previously reported far-infrared laser lines have been measured to an accuracy of 100 kHz. These laser lines were measured using a heterodyne system which allowed for more ...accurate measurement. The four far-infrared laser lines which originated from Formic Acid (HCOOH), O-Deutero-Formic Acid (HCOOD), C-Deutero-Formic Acid (DCOOH), and Methyl Chloride (CH 3 Cl) were optically pumped by a highly stable, grating-tunable, CO 2 laser. Three of the far-infrared laser lines have been measured previously using Fabry-Perot cavities not typicaly known for their high accuracy. The fourth far-infrared laser line had been measured previously by heterodyne methods but under nonoptimal conditions. The difference between the frequencies measured here and the listed frequencies for these laser lines ranged from 0.9 MHz to 3.9 GHz.
This paper introduces an innovative method to control and select transverse mode pattern in a He–Ne laser. The cat’s eye cavity is established by using a cat’s eye reflector as the reflecting mirror. ...Laser transverse mode pattern varies continuously when the distance between the convex lens and the concave mirror is changed, which form the cat’s eye reflector. By Newton–Cotes method, the numerical solution of two-dimensional diffraction integral equation in the cat’s eye cavity is obtained, the laser operating modes under various parameters are analyzed, and the eigenvalue ηmn and diffraction power loss corresponding with every transverse mode are calculated. The parameters assuring fundamental transverse mode output are figured out, which match the experiment results well. Therefore, a new convenient real-time means for the control and selection of the laser transverse mode is realized.
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