Spontaneous Raman spectroscopy of tungstate and molybdate crystals for Raman lasers

The design and operation of solid-state Raman lasers

After a brief examination of known insulating laser crystals and the stimulated emission channels of their generating activator ions, this article reviews recent advances in the development of novel lasing crystals and ceramics, as well as inorganic and organic nonlinear-laser crystals for χ(3) and cascaded χ(3) ↔ χ(2) frequency converters Several new modern attractive technologies in the physics and techniques of crystalline lasers are also discussed

https://onlinelibrary.wiley.com/doi/pdf/10.1002/lpor.200710008

Laser crystals and ceramics: recent advances

Temperature is important because it has an effect on even the tiniest elements of daily life and is involved in a broad spectrum of human activities. That is why it is the most commonly measured physical quantity. Traditional temperature measurements encounter difficulties when used in some emerging technologies and environments, such as nanotechnology and biomedicine. The problem may be alleviated using optical techniques, one of which is luminescence thermometry. This paper reviews the state of luminescence thermometry and presents different temperature read-out schemes with an emphasis on those utilizing the downshifting emission of lanthanide-doped metal oxides and salts. The read-out schemes for temperature include those based on measurements of spectral characteristics of luminescence (band positions and shapes, emission intensity and ratio of emission intensities), and those based on measurements of the temporal behavior of luminescence (lifetimes and rise times). This review (with 140 references) gives the basics of the fundamental principles and theory that underlie the methods presented, and describes the methodology for the estimation of their performance. The major part of the text is devoted to those lanthanide-doped metal oxides and salts that are used as temperature probes, and to the comparison of their performance and characteristics.

/pdf/sensing-temperature-via-downshifting-emissions-of-lanthanide-5538kt617s.pdf

Sensing temperature via downshifting emissions of lanthanide-doped metal oxides and salts. A review.

The standard and anomalous crystal-field spectra of Eu3+

Raman spectroscopy of crystals for stimulated Raman scattering

Calcium niobium gallium and calcium lithium niobium gallium garnets doped with rare earth ions––effective laser media

Results on spontaneous Raman spectroscopy of alkaline-earth tungstate crystals are presented. The frequency of the modes active in stimulated Raman scattering (SRS) modes was found to increase and their width to decrease with increasing cation radius and mass in the series of alkaline-earth (Ca, Sr, Ba) tungstates. High peak values of the Raman scattering cross section for barium and strontium tungstate crystals — new media offering promise for SRS — were predicted and observed in the experiments. Laser experiments on the SRS threshold showed that the SRS gain for the barium tungstate crystal was close to the record value observed for the barium nitrate crystal, which is extensively used in SRS.

https://iopscience.iop.org/article/10.1070/QE2000v030n01ABEH001658/pdf

Stimulated Raman scattering in alkaline-earth tungstate crystals

Disordered garnets Ca3(Nb, Ca)5O12:Nd3+ grown by the Czochralski method are used in a pulsed picosecond laser to generate 5–10-ps pulses in passive mode-locking trains of 120–180 ns and 1.6 mJ of energy at 1.06 μm. The evolution of the pulse parameters along the train is investigated. Direct time-resolved measurements allow us to determine the positive linear chirp of the laser frequency, which causes the pulse spectral broadening of Δν = 50–60 cm−1. The chirped pulses are compressed in the external grating compressor. The measured pulse duration of 2 ps is limited by the time resolution of the streak camera.

Alexander A. Sobol

Papers

Spontaneous Raman spectroscopy of tungstate and molybdate crystals for Raman lasers

Raman spectroscopy of crystals for stimulated Raman scattering

Calcium niobium gallium and calcium lithium niobium gallium garnets doped with rare earth ions––effective laser media

Stimulated Raman scattering in alkaline-earth tungstate crystals

Disordered garnets Ca3(Nb, Ga)5O12:Nd3+- prospective crystals for powerful ultrashort-pulse generation.