scholarly journals Spectroscopic analysis of a-C and a-CNx films prepared by ultrafast high repetition rate pulsed laser deposition

2005 ◽  
Vol 97 (7) ◽  
pp. 073522 ◽  
Author(s):  
R. McCann ◽  
S. S. Roy ◽  
P. Papakonstantinou ◽  
J. A. McLaughlin ◽  
S. C. Ray
2013 ◽  
Vol 278 ◽  
pp. 67-70 ◽  
Author(s):  
M. Pervolaraki ◽  
Ph. Komninou ◽  
J. Kioseoglou ◽  
G.I. Athanasopoulos ◽  
J. Giapintzakis

2009 ◽  
Vol 203 (8) ◽  
pp. 1055-1058 ◽  
Author(s):  
D. Craciun ◽  
G. Socol ◽  
N. Stefan ◽  
I.N. Mihailescu ◽  
G. Bourne ◽  
...  

2013 ◽  
Vol 40 (6) ◽  
pp. 0608003
Author(s):  
冯国斌 Feng Guobin ◽  
王振宝 Wang Zhenbao ◽  
冯刚 Feng Gang ◽  
杨鹏翎 Yang Pengling ◽  
王群书 Wang Qunshu ◽  
...  

2003 ◽  
Vol 780 ◽  
Author(s):  
B. Luther-Davies ◽  
V. Z. Kolev ◽  
M. J. Lederer ◽  
R. Yinlan ◽  
M. Samoc ◽  
...  

AbstractUltra-fast pulsed laser deposition using high-repetition-rate short-pulse lasers has been shown to provide high optical quality, super smooth thin films free of scattering centres. The optimized process conditions require short ps or sub-ps pulses with repetition rate in the range 1-100 MHz, depending on the target material. Ultra-fast pulsed laser deposition was used to successfully deposit atomically-smooth, 5micron thick As2S3 films. The as-deposited films were photosensitive at wavelengths close to the band edge (≈520 nm) and waveguides could be directly patterned into them by photo-darkening using an Argon ion or frequency doubled Nd:YAG laser. The linear and nonlinear optical properties of the films were measured as well as the photosensitivity of the material. The optical losses in photo-darkened waveguides were <0.2 dB/cm at wavelengths beyond 1200nm and <0.1 dB/cm in as-deposited films. The third order nonlinearity, n2,As2S3, was measured using both four-wave mixing and the z-scan technique and varied with wavelength from 100 to 200 times fused silica (n2,Silica ≈3×10-16 cm2/W) between 1500nm and 1100nm with low nonlinear absorption.Encouraged by the Ultrafast laser deposition results, we have built a new specialized modelocked picosecond laser system for deposition of optical films and for laser formation of nanoclusters. The newly developed “state of the art” powerful Nd:YVO laser can operate over a wide range of wavelengths, intensities, and repetition rates in MHz range. A brief description of the 50W laser installation is presented.


2019 ◽  
Vol 9 (7) ◽  
pp. 1289 ◽  
Author(s):  
Mateusz Żbik ◽  
Piotr Wieczorek

Most modern pulsed laser systems require versatile laser diode drivers. A state-of-the-art pulsed laser driver should provide precise peak power regulation, high repetition rate, and pulse duration control. A new, charge line dual-FET transistor circuit structure was developed to provide all these features. The pulsed modulation current is adjustable up to Imax = 1.2 A, with the laser diode forward voltage acceptable up to UF max = 20 V. The maximum repetition rate is limited by a charge line circuit to frep max = 20 MHz. Compared to the conventional single transistor drivers, the solution proposed in this paper allows a precise, high resolution width regulation to be obtained, whereas a low pulse jitter is ensured. In the solution, two separate, out-of-phase signals are used to trigger the individual Field Effect Transistors (FET). The resultant pulsed modulation current full-width-at-half-maxima (FWHM) is regulated from ~200 ps up to 2 ns. All control and timing signals are generated with a popular Field-Programmable Gate Array (FPGA) digital circuitry. The use of standard FPGA devices ensures the low cost and high reliability of the circuit, which are not available in laser drivers consisting of sophisticated analogue adjustable delay circuits.


2013 ◽  
Vol 114 (2) ◽  
pp. 625-629
Author(s):  
Tetsuya Shimogaki ◽  
Taihei Ofuji ◽  
Norihiro Tetsuyama ◽  
Kota Okazaki ◽  
Mitsuhiro Higashihata ◽  
...  

APL Materials ◽  
2016 ◽  
Vol 4 (12) ◽  
pp. 126109 ◽  
Author(s):  
H. Schraknepper ◽  
C. Bäumer ◽  
F. Gunkel ◽  
R. Dittmann ◽  
R. A. De Souza

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