Laser induced birefringence

S. Ivanov, I. Yakovlev, S. Kostromin, V Shivaev, L. Lasker, J. Stumpe, and D. Kreysig, Laser-induced birefringence in homeotropic films of photochromic comb-shaped liquid-crystalline copolymers with azobenzene moieties at different temperatures, Makromol. Chem. Rapid... 

S. Cavalieri, M. Matera, F.S. Pavone, J. Zhang, P. Lambropoulos, T. Nakajima, High-sensitivity study of laser-induced birefringence and dichroism in the ionization continuum of cesium, Phys. Rev. A 47 (1993) 4219. 

The utility of laser-induced birefringence is based on the high frequency of the perturbation field used, which allows only electronic polarization to occur. If the duration of the laser pulse is sufficiently long, the induced dipoles are partially reoriented parallel to the E of the laser pulse. Comparison of the rate and amplitude of the resulting birefringence with that observed in square-pulse (dc) experiments permits elucidation of the contributions of different polarization mechanisms to the induced dipole moment of the particles [27]. 

Fig.7.41a-c. Comparison of different techniques for measuring the neon transition ls2 — 2p2 at X = 588.2 nm (a) intracavity saturation spectroscopy (Lamb peak of the laser output Il cd) with Doppler-broadened background) (b) laser-induced dichroism and (c) laser-induced birefringence [7.72]... 

Borrelli N. F., Smith C. M., Price J. J., and Allan D. C., Polarized excimer laser-induced birefringence in silica, Appl Phys. Lett., 80,1433902 (2002). 

Fig. 10,45. Comparison of sa-turated absorption (a), laser-induced dichroism (b), and laser-induced birefringence spectrum (c) of the Is2-2p2 neon transition atx= 588.2 nm [10.62]...

The optical system used to assess flow-induced birefringence consisted of a 2-mW polarized He-Ne laser focused by a condenser lens on the center of the flow field. The birefringence patterns are observed between crossed polars by using a quarter wave (X/4) retardation plate as a Senarmont compensator. The polarized laser has an extinction ratio of 100 1 the polarizer and analyzer are Carl Zeiss components with extinction ratios of approximately 10... 

LBR low birefringence LIPP laser-induced pressure pulse... 

Figure 6 Oscilloscope trace of a linearly polarized laser step pulse used for perturbation in laser-induced electrical birefringence experiments. The pulse is generated by a Nd YAG laser operated in the fixed-0, TEMqo mode and terminated by the combined use of intra- and extracavity Pockels cells. I, light intensity scale 20 mV/100 /xs. (Reprinted with permission from Ref 27. Copyright 1995 American Chemical Society)...

Shoji I, Taira T, Ikesue A (2007) Thermally-induced-birefringence effects of highly Nd " -doped Y3AI5O12 ceramic lasers. Opt Mater 29 1271-1276... 

Ostermeyer M, Mudge D, Veitch PJ, Munch J (2006) Thermally induced birefringence in Nd YAG slab lasers. Appl Opt 45 5368-5376... 

Doppler-Free Laser-Induced Dichroism and Birefringence... 

Fig. 2.45 Experimental arrangement for observation of Doppler-free laser-induced dichroism and birefringence [274]...

C. Delsart, J.C. KeUer, Doppler-free laser induced dichroism and birefringence, in Laser Spectroscopy of Atoms and Molecules, ed. by H. Walther. Topics Appl. Phys., vol. 2... 

Cylindrically symmetric optical fibers are theoretically not birefringent, however, in practice bends and twists induce birefringence in optical fibers, which can modify the state of polarization of light in an unpredictable way as it propagates through the fiber. The performance of many devices used in optical fiber lasers (e.g., electro-optic modulators) is polarization-dependent, so it is often necessary to control the polarization state of light at some point in the fiber and/or compensate for unwanted birefringence. 

FIGURE 28 (a) Random molecular orientation in a liquid with anisotropic molecules produces an isotropic refractive index, (b) Partial alignment with a laser beam produces a nonlinear index and optically induced birefringence. 

Optical Kerr Effect. Another important method used to characterize polymers is the optical Kerr effect (OKE). The optical Kerr effect differs from the quadratic electrooptic effect in that the birefringence effects are induced solely by an optical field (37). In this measurement, an intense linearly polarized pump pulse induces birefringence in the nonlinear sample through an intensity-dependent refractive index change. The sample is placed between crossed polarizers and a weak, typically tunable, continuous wave (cw) probe laser (usually at a different wavelength and polarized at 45° to the pump pulse) overlaps the pumped region. The increased transmission of the probe beam when the pump pulse arrives is proportional to (Xeff), a combination of elements of the tensor. Many... 

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