Jean-Pierre Boquillon

50 mJ/30 ns FTIR Q-switched diode-pumped Er:Yb:glass 1.54 μm laser

Abstract 50 mJ Q-switched output at 30 ns pulse duration was demonstrated with a transversely diode-pumped bulk Er 3+ :Yb 3+ :glass 1.54 μm laser system of uncomplicated and compact design, using a piezoelectrically driven FTIR shutter. In long-pulse operation, 360 mJ output was obtained for 2.65 J incident optical pump energy. Maximum optical slope efficiencies of 20.5% and 5.4% were measured in long-pulse and Q-switched operation, respectively. Optimum Q-switch timing was studied taking into account the Yb 3+ →Er 3+ energy transfer process and was correlated with free-running delay parameters.

1.65-μm Er:Yb:YAG diode-pumped laser delivering 80-mJ pulse energy

We demonstrate efficient lasing of bulk diode-pumped Er 31 :Yb 31 :YAG at 1.645 mm. The material is transversely pumped using three quasi-cw 960-nm laser diode arrays in a simple arrangement. In the free-running mode of operation, an output pulse energy of 79 mJ is obtained at 4.7 J of incident optical pump energy. The lasing threshold lies in the range 1.0 to 1.9 J in long-pulse operation, depending on pumping conditions, and optical slope efficiencies of 2.2% to 3.4% were measured with respect to the incident pump energy. Furthermore, initial Q-switching experiments with a Co:MALO saturable absorber yielded pulses of 1.7-mJ energy and 340-ns FWHM duration. As the reported laser setup also has an uncomplicated and compact design, it represents a good crystalline rare-earth candidate system with superior material qualities to compete against the established glass-host materials in the eye-safe wavelength range.

Flashlamp-pumped Ti:Sapphire laser with different rods grown by Czochralski and Verneuil methods

The design and the development of a flashlamp-pumped Ti:Sapphire laser is described. Design criteria are discussed and performance improvements using different types of fluorescent UV converters or filters, such as organic dyes or doped glass are presented. We have tested different laser rods at various Ti-concentrations obtained by Verneuil or Czochralski growth techniques. The maximum laser output energy of 540 mJ with a differential efficiency up to 1% was achieved by using only a pyrex filter surrounding the laser rod.

Lasing characteristics of a new DCM derivative under flashlamp pumping

Abstract A new DCM derivative (4-dicyanomethylene-2-methyl-6-p-diethanolamino-styryl 4H-pyran or DCM-OH), was tested under flashlamp pumping. This dye lased in the 600–700 nm range with efficiency up to 0.4% at maximum. Lasing performances of DCM-OH in methanol and water-methanol mixture are reported and compared to normal DCM.

80-mJ/1.64-μm pulsed Er:Yb:YAG diode-pumped laser

Efficient lasing at 1.645mm of bulk diode-pumped Er3+:Yb3+:YAG is demonstrated. The material is transversely pumped using three quasi-cw 960-nm laser-diode arrays in a simple arrangement. In free-running mode of operation, output pulse energy of 79mJ is obtained at 4.7J of incident optical pump energy. Lasing threshold lies in the range of 1.0-1.9J in long-pulse operation, depending on pumping conditions, while optical slope efficiencies of 2.2-3.4% were measured with respect to the incident pump energy. Furthermore, initial Q-switching experiments with a Co:MALO saturable absorber yielded pulses of 1.7mJ energy and 340ns FWHM duration. As the reported laser setup is also characterized by an uncomplicated and compact design, it represents a good crystalline rare-earth candidate system with superior material qualities to compete against the established glass-host materials in the eyesafe wavelength range.

Laser cleaning of oxidized metallic materials: role of the optical properties of the oxide films

In the present work, the effects of nanosecond pulsed laser irradiation on oxidized metallic surfaces were investigated, in order to estimate the possibility of using laser techniques for cleaning applications. After oxidation, the oxide layer developed on the metallic surfaces depends on the composition of the substrate and also on oxidation conditions. In this study a modeling system: pure Fe oxidized at 500 degrees C, has been investigated. The influence of the optical properties of the oxide films on the removal mechanisms and the cleaning efficiency of the laser technique was illustrated by performing specific electrochemical treatments.

Pulse timing effects in bulk Er/Yb codoped diode-pumped eyesafe lasers

In this work, diode-pumping with appropriately modulated pulses is used to expose subtle input / output pulse-timing characteristics of Er3+ /Yb3+ systems, study their relation to laser efficiency and demonstrate some unique laser-pulse timing behavior. Er+3/Yb+3 codoped glass and YAG laser-host materials with similar concentrations (optimized for eyesafe emission in the 1.6-mum region) were studied in the same diode-pumped setup, in similar resonator configurations and analogous operating conditions.

High performance, diode-pumped, Q-switched Er:Yb:glass laser with FTIR shutter

Summary form only. Q-switched erbium-laser pulse energies at /spl lambda/=1.54 /spl mu/m have generally been severely limited due to low damage threshold of the electro-optic modulator materials presently available at this wavelength and due to the polarization sensitivity of the usual electrooptic shutters. Here, by employing the frustrated total internal reflection (FTIR) Q-switching scheme in a diode-pumped Er:Yb:glass laser, we demonstrate that record-high nanosecond-pulse energies can be obtained from such a compact system.

CW diode end-pumped Nd:YAP laser at 1.34 /spl mu/m

Summary form only given.We have studied the Nd:YAP laser crystal, also named Nd:YAlO/sub 3/. The main interests of the YAP crystal is to exhibit high conductivity and hardness combined with a low laser threshold like the most common Nd: YAG crystal. But the most important reason is the large branching ratio for /sup 4/F/sub 3/2//spl rarr//sup 4/I/sub 11/2/ transitions, which makes Nd:YAP very attractive for operation at 1.34 /spl mu/m. Some experiments around 1.3 /spl mu/m have shown that Nd: YAP was more efficient than Nd:YAG under flashlamp pumping. This paper presents the results obtained with the Nd:YAP compared with the Nd:YAG around 1.3 and 1.0 /spl mu/m. To our knowledge this is the first study of a multiwatt diode-pumped laser system based on the Nd:YAP crystal.