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1.
This paper gives an overview of the results obtained with diode‐pumped Neodymium‐doped crystals operating below 900 nm. Operation at such low wavelengths requires considering the strong thermal population of the lower level of the laser transition. Based on a theoretical study and simulations, the paper presents the challenges related to the design of these three‐level lasers. Experimental results are given with Nd:YAG and Nd:vanadate crystals. It is explained how to deal with the line competition with emission at 946 nm or 912 nm. Finally, intracavity second‐harmonic generation is presented. The output powers reach a few hundred mW at wavelengths below 450 nm. Hence, the paper demonstrates the potential of Nd‐doped diode‐pumped solid‐state lasers for applications in the blue range, in replacement of gas lasers such as helium‐cadmium lasers. 相似文献
2.
Mathew George Raimund Ricken Viktor Quiring Wolfgang Sohler 《Laser \u0026amp; Photonics Reviews》2013,7(1):122-131
The fabrication by diffusion doping and a detailed optical investigation of a Ti:Tm:LiNbO3 waveguide amplifier and of a Fabry‐Pérot type Ti:Tm:LiNbO3 laser are reported. Both devices are in‐band pumped by a laser diode at 1650 nm. The wave‐guide amplifier shows broad‐band optical gain in the wavelength range 1750 nm < λ < 1900 nm. The laser emits at 1890 nm, the longest emission wavelength of a Tm:LiNbO3 laser reported so far; also 1850 nm emission could be demonstrated. Laser threshold (1890 nm) is at 4 mW coupled pump power; the slope efficiency is ∼13.3%. Properties and potential of both devices are analyzed by extensive modeling. 相似文献
3.
In this work, recent progress in the theoretical and experimental studies of optical‐fiber microcoil waveguides and resonators, as well as their various applications are reviewed. In particular, the focus is set on sensing and interferometry applications. It is shown that due to its inherently low propagation and fiber‐coupling losses, fiber‐microcoil based sensors and interferometers offer substantial enhancement of sensitivity and compactness compared to other types of devices. Recent progress in the realization and experimental characterization of such structures is presented and the theoretical tools to analyze the impact of real‐world nonuniformities on the characteristics of fiber‐microcoil structures are provided. 相似文献
4.
C. Cuadrado‐Laborde A. Díez J.L. Cruz M.V. Andrs 《Laser \u0026amp; Photonics Reviews》2011,5(3):404-421
The interest in all‐fiber lasers is stimulated by the inherent advantages they have over bulk lasers in aspects such as heat dissipation and robustness. The performance of Q‐switched and modelocked fiber lasers can benefit enormously from the development of all‐fiber configurations. A fiber laser with strictly all‐fiber components can fulfil the requirements of mechanical stability, low maintenance, enhanced power efficiency, simplified assembly process, and low cost. In this framework, recent developments infiber acousto‐optic devices are reviewed that have demonstrated new possibilities for actively Q‐switched distributed feedback fiber lasers, modelocking lasers and doubly active Q‐switched modelocked lasers. The aim is to demonstrate the great potential of infiber devices for the active control of different types of fiber lasers. 相似文献
5.
N.D. Lai M. Brunel F. Bretenaker O. Emile 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,19(3):403-410
We study theoretically and experimentally different methods to control the pulses emitted by solid-state lasers passively
Q-switched by a saturable absorber. We explore one- and two-axis laser schemes allowing to control the pulse duration, which
is ruled by the saturation powers of the transitions in the absorber and in the gain medium. In one-axis lasers, it is shown
that the adjustment of the pump and laser beam sizes in the active medium and in the absorber provides an efficient means
to control the pulse temporal shape and duration. Furthermore, a two-axis laser cavity supporting so-called forked-eigenstate
operation permits to freely adjust the parts of the mode power which circulate in the gain medium and in the absorber. In
this case, a lengthening of the pulse duration up to 500 ns is obtained with an increase of the average output power. The
theoretical results obtained by using rate equations adapted to each cavity geometry are in close agreement with experiments
performed on a diode-pumped Nd3+:YAG laser Q-switched by a Cr4+:YAG saturable absorber. The relevance of the different techniques to control the pulse durations in the framework of potential
applications is discussed.
Received 3 December 2001 相似文献
6.
At the Prague Asterix Laser System Center (PALS) the Asterix iodine laser delivering up to 700 J/0.5 ns is used as a pump
source for X-ray laser experiments and applications. The prepulse technique was applied which is known to improve the neon-like
X-ray laser output at the J = 0-1 transition dramatically. Since Zn slab targets were used the operating wavelength was 21.2 nm. A prepulse having up
to 20 J precedes the main pulse by 10 ns. The main beam and the prepulse beam are focussed by two different optical systems
separately and their foci are superimposed at the target surface. By implementing a half-cavity set-up for double-pass amplification
using a Mo/Si multilayer mirror - which can be used for more than 100 shots - the X-ray laser output was more than 10 times
stronger than at the single pass in a 30 mm long plasma. Double-pass amplification was observed to be most efficient when
the pump pulse duration was at least 150 ps longer than the round trip time ( ≈ 260 ps) in the half-cavity. Under this fundamental
condition the X-ray laser reached saturation in the double-pass regime containing approx. 4 mJ energy which has been proved
to be enough for future applications. In this contribution, the X-ray laser features like divergence in two dimensions, the
beam quality (symmetry), the pointing angle and the integrated intensity giving an estimation of the output energy are investigated
over 110 shots. To characterize the stability of the X-ray laser the shot distribution, the mean value and the standard deviation
for these parameters are evaluated. For 18 shots in a series - what was achievable during one day - the corresponding values
are given, and a statistical analysis carrying out a chi-squared test characterize the Zn X-ray laser as a robust tool suitable
for applications. In the future it is planned to allocate X-ray laser beam time to external research groups.
Received 17 May 2002 / Received in final form 10 September 2002 Published online 6 November 2002
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ID="a"e-mail: praeg@fzu.cz 相似文献