Q-switching with single crystal photo-elastic modulators

Bammer, F.; Petkovšek, Rok

doi:10.1117/12.880816

Cited by 4 publications

(6 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this configuration the response of transmission to an additional retardation imposed by the PEM is linear, i.e. 2Δδ = ΔT or 2δ 1 = T 1 in terms of oscillation amplitudes [8] , such that even small retardation amplitudes can be detected. The transmission is 50% when the PEM is at rest and when it works e.g.…”

Section: Crystal-cut and Experimental Setupmentioning

confidence: 99%

“…This constraint depends of course on the precision settings of a certain application. For a given allowed deviation q of transmission the following formula holds in case of linear polarized light [8] :…”

Section: Acceptance Anglementioning

confidence: 99%

“…This configuration usually allows for 3m-crystals the excitation of a longitudinal oscillation mode in x-direction as indicated in Figure 1. Furthermore a thickness-oscillation mode in ydirection and a yz-shear oscillation mode can be excited due to the form of the piezo-matrix [8,15] . We use a BBO-crystal with the dimensions 8.6x4.05x4.5mm in x-, y-and z-direction, gold electrodes on the zx-surfaces and AR-coating for 633nm on the xy-surfaces.…”

Section: Crystal-cut and Experimental Setupmentioning

confidence: 99%

See 2 more Smart Citations

A new material for single crystal modulators: BBO

2011

Self Cite

View full text Add to dashboard Cite

Single crystal photo-elastic modulators (SCPEM) are based on a single piezo-electric crystal which is electrically excited on a resonance frequency such that the resulting resonant oscillation causes a modulated artificial birefringence due to the photo-elastic effect. Polarized light experience in such a crystal a strong modulation of polarization, which, in connection with a polarizer, can be used for Q-switching of lasers with pulse repetition frequencies in the range of 100-1000 kHz. A particularly advantageous configuration is possible with crystals from the symmetry class 3m. Besides LiTaO 3 and LiNbO 3 , both already well explored as SCPEM-materials, we introduce now BBO, which offers a very low absorption in the near infrared region and is therefore particularly suited for Q-switching of solid state lasers. We demonstrate first results of such a BBO-modulator with the dimensions 8.6 x 4.05 x 4.5mm in x-, y-, z-direction, which offers a useful resonance and polarization modulation at 131.9 kHz. Since the piezo-electric effect is small, the voltage amplitude for achieving Q-switching for an Nd:YAG-laser is expected to be in the range of 100V. Nevertheless it is a simple and robust device to achieve Q-switching with a high fixed repetition rate for high power solid state lasers.

show abstract

Section: Crystal-cut and Experimental Setupmentioning

confidence: 99%

Section: Acceptance Anglementioning

confidence: 99%

Section: Crystal-cut and Experimental Setupmentioning

confidence: 99%

See 1 more Smart Citation

A new material for single crystal modulators: BBO

2011

Self Cite

View full text Add to dashboard Cite

show abstract

“…A Single Crystal PhotoElastic Modulator (SCPEM) [7] modulates the polarisation of light due to the photoelastic effect. It is a piezoelectric optical transparent crystal that is electrically excited at one of its resonance frequencies.…”

Section: Scpemmentioning

confidence: 99%

Polarisation Measurement of the Emitted Thermal Radiation During Laser Material Processing

Humenberger¹,

Liedl²,

Bammer³

et al. 2018

Proceedings of the 29th International DAAAM Symposium 2018

View full text Add to dashboard Cite

We present a new approach for quality control in laser material processing. By means of an active optical element (SCPEM -Single Crystal PhotoElastic Modulator) the emitted thermal radiation from the interaction zone of the focused laser radiation with the material surface is to be detected in order to determine a correlation to the process parameters from the polarisation state of the radiation. Due to the dependence of polarised radiation on the emission angle, the inclination of the interaction zone in the observed area can be deduced. For this purpose, an optomechanical setup for measuring two orthogonal polarisation directions of the emitted thermal radiation has been developed and a data acquisition system has been implemented. The amplitudes of two orthogonal polarisation directions could be determined from the signal modulated by the SCPEM during tests on different experimental setups. From the ratio of these polarisation components, emission angles can be derived using the Fresnel equations.

show abstract

“…This is a piezoelectric crystal, excited on a resonance frequency, to modulate the polarization of light by its stress-induced birefringence (photoelastic effect) [9]. Its functionality is the same as that of a conventional PEM [10], which is based on a glassblock excited by a piezo-element.…”

Section: Polarization Modulationmentioning

confidence: 99%

Inline imaging-ellipsometer for printed electronics

Huemer

Jamalieh

Bammer

et al. 2016

Tm - Technisches Messen

View full text Add to dashboard Cite

Abstract:Printed electronics, e.g. organic photo-voltaic, are usually produced by roll-to-roll printing. For this fast growing market no inline-measurement method for 2D-thickness-distributions after printing exists. In many cases layer-thicknesses are in the sub-μm-range, e.g.10-300 nm, and ellipsometry is one typical technology for this range, but up to now only in the laboratory, since most ellipsometers are too slow and/or measure only a spot. A new concept, a stroboscopic imaging ellipsometer, enables fast measurement on a line, to acquire the 2D-distribution of thickness, right after printing.Keywords: Imaging-ellipsometry, printed electronics, R2R-production, thickness-control. Zusammenfassung

show abstract

Q-switching with single crystal photo-elastic modulators

Cited by 4 publications

References 15 publications

A new material for single crystal modulators: BBO

A new material for single crystal modulators: BBO

Polarisation Measurement of the Emitted Thermal Radiation During Laser Material Processing

Inline imaging-ellipsometer for printed electronics

Contact Info

Product

Resources

About