Calibration of pulsed laser wavelength by optogalvanic spectroscopy in hollow cathode discharges

1993 ◽  
Vol 42 (2) ◽  
pp. 251-254 ◽  
Author(s):  
S. Levesque ◽  
F. Babin ◽  
J.-M. Gagne
Keyword(s):  
Hollow Cathode ◽  
Pulsed Laser ◽  
Laser Wavelength ◽  
Optogalvanic Spectroscopy

scholarly journals Effects of Pulse Duration and Heat on Laser-Induced Periodic Surface Structures

2020 ◽  
Vol 14 (4) ◽  
pp. 552-559
Author(s):  
Shuhei Kodama ◽  
Keita Shimada ◽  
Masayoshi Mizutani ◽  
Tsunemoto Kuriyagawa ◽  
◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Pulse Duration ◽  
Pulse Laser ◽  
Pulsed Laser ◽  
Laser Wavelength ◽  
Surface Structures ◽  
Pulsed Lasers ◽  
Efficient Technology ◽  
Periodic Surface ◽  
Ultrashort Pulsed Lasers

Compared with traditional nanotexturing methods, an ultrashort-pulsed laser is an efficient technology of fabricating nanostructures called laser-induced periodic surface structures (LIPSS) on material surfaces. LIPSS are easily fabricated when the pulse duration is shorter than collisional relaxation time (CRT). Accordingly, ultrashort-pulsed lasers have been mainly used to study LIPSS, but they unstably irradiate while requiring high costs. Although long-pulsed lasers have low cost and high stability, the phenomena (such as the effect of pulse duration, laser wavelength, and heat) of the LIPSS fabricated using short-pulsed lasers with the pulse duration close to the maximum CRT, which is greater than femtosecond, have not been clarified. However, the nanosecond pulse laser has been reported to produce LIPSS, but those were unclear and ununiform. In this study, the short-pulsed laser with the pulse duration of 20 ps, which is close to the maximum CRT, was employed to clarify the effects of pulse duration and heat on the fabrication of LIPSS and to solve problems associated with ultrashort-pulsed lasers. First, a finite-difference time-domain simulation was developed at 20-ps pulse duration to investigate the effects of irradiation conditions on the electric-field-intensity distribution. Subsequently, experiments were conducted using the 20-ps pulse laser by varying conditions. The aspect ratio of the LIPSS obtained was greater than that of the LIPSS fabricated using ultrashort-pulsed lasers, but LIPSS were not fabricated at 355- and 266-nm laser wavelength. In addition, the short-pulsed laser experienced thermal influences and a cooling material was effective for the fabrication of LIPSS with high-aspect-ratio. This demonstrates the effects of pulse duration close to the CRT and heat on the fabrication of LIPSS.

Fizeau wavemeter for pulsed laser wavelength measurement

1984 ◽  
Vol 23 (21) ◽  
pp. 3862 ◽  
Author(s):  
Mark B Morris ◽  
Thomas J. McIlrath ◽  
James J. Snyder
Keyword(s):  
Pulsed Laser ◽  
Laser Wavelength ◽  
Wavelength Measurement

Comment on “Invalidation of the Intracavity Opto-galvanic Method for Radiocarbon Detection” by Cantwell G Carson, Martin Stute, Yinghuang Ji, Roseline Polle, Arthur Reboul, and Klaus S Lackner

Radiocarbon ◽  
2016 ◽  
Vol 58 (1) ◽  
pp. 227-230 ◽  
Author(s):  
Daniel E Murnick
Keyword(s):  
Narrow Band ◽  
Single Mode ◽  
Laser Wavelength ◽  
Absorption Model ◽  
Linear Absorption ◽  
Broadband Absorption ◽  
Laser Gain ◽  
Cell Discharge ◽  
Optogalvanic Spectroscopy ◽  
Gain Profile

AbstractCarson et al. (2016) have measured the optogalvanic response of an intracavity cell discharge containing carbon dioxide enriched in radiocarbon in a 14CO2 laser, and compared same to an unenriched sample. The measurement was carried out by modulating the laser wavelength while slowly tuning through the laser gain profile. The results of the measurements are claimed to “invalidate the optogalvanic method for radiocarbon detection.” A broadband linear absorption model is presented in support of this hypothesis. In fact, the experimental design was such as to minimize any possibility for 14C detection, and the model presented is not relevant to their experiment. Crucial control measurements were not carried out and the model used did not differentiate between broadband absorption spectroscopy and intracavity optogalvanic spectroscopy (ICOGS) with a narrow-band single-mode CO2 laser.

Growth of BN Thin Films by Pulsed Laser Deposition

1991 ◽  
Vol 235 ◽  
Author(s):  
J. A. Knapp
Keyword(s):  
Pulsed Laser Deposition ◽  
Room Temperature ◽  
Pulsed Laser ◽  
Laser Wavelength ◽  
Laser Deposition ◽  
Strong Function ◽  
Ablation Plasma ◽  
Clean Sample

ABSTRACTA new UHV system for pulsed laser deposition of materials is described, together with results from preliminary experiments for depositions of BN on Si. The system is designed to allow for in-situ diagnostics of the ablation plasma, as well as UHV preparation and characterization of clean sample substrates. The room temperature depositions of BN result in amorphous, B-rich films, whose particle content is a strong function of laser wavelength.

The effects of substrate temperature and laser wavelength on the formation of carbon thin films by pulsed laser deposition

1999 ◽  
Vol 8 (2-5) ◽  
pp. 463-467 ◽  
Author(s):  
Tsuyoshi Yoshitake ◽  
Takashi Nishiyama ◽  
Hajime Aoki ◽  
Koji Suizu ◽  
Koji Takahashi ◽  
...  
Keyword(s):  
Thin Films ◽  
Substrate Temperature ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Laser Wavelength ◽  
Laser Deposition ◽  
Carbon Thin Films
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