Generation of a radially polarized laser beam in a single microchip Nd:YVO_4 laser

Wei, Ming-Dar; Lai, Yi Shen; Chang, Kai Cheng

doi:10.1364/ol.38.002443

Cited by 33 publications

(15 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The extra-cavity generation of such beams has been achieved by using an interference approach [12,22,23], liquid crystals [24,25], sub-wavelength grating [26] and from a spirally varying retarder [27]. Laser cavities have been customized to produce particular CV beams by techniques such as inducing thermal stress to isotropic gain media [28], by exploiting the thermal birefringence of laser gain media [29][30][31], with the use of an intracavity axicon [32][33][34] and with a conical shaped pump beam [35][36][37]. The poles of the HOP sphere represent scalar vortex beams (having helical wavefronts) with a uniform circular polarization (right circular at the north pole and left circular at the south pole).…”

Section: Introductionmentioning

confidence: 99%

Controlled generation of higher-order Poincaré sphere beams from a laser

et al. 2016

View full text Add to dashboard Cite

The angular momentum state of light can be described by positions on a higher-order Poincaré (HOP) sphere, where superpositions of spin and orbital angular momentum states give rise to laser beams that have found many applications, including optical communication, quantum information processing, microscopy, optical trapping and tweezing and materials processing. Many techniques exist to create such beams but none to date allow their creation at the source. Here we report on a new class of laser that is able to generate all states on the HOP sphere. We exploit geometric phase control with a non-homogenous polarization optic and a wave-plate inside a laser cavity to map spin angular momentum (SAM) to orbital angular momentum (OAM). Rotation of these two elements provides the necessary degrees of freedom to traverse the entire HOP sphere. As a result, we are able to demonstrate that the OAM degeneracy of a standard laser cavity may be broken, producing pure OAM modes as the output, and that generalized vector vortex beams may be created from the same laser, for example, radially and azimuthally polarized laser beams. It is noteworthy that all other aspects of the laser cavity follow a standard design, facilitating easy implementation.

show abstract

Section: Introductionmentioning

confidence: 99%

Controlled generation of higher-order Poincaré sphere beams from a laser

et al. 2016

View full text Add to dashboard Cite

show abstract

“…The mechanism of higher transverse mode operation is not clear now. However, the introduction of polarization anisotropy for reflectivity induced by slight tilting of a cavity mirror may be of great help in the selection of polarization state [12]. Figure 7 shows the total intensity distribution and the intensity distributions after passage of a linear polarizer for the Bessel-Gaussian beam with m 5.…”

Section: (B) Figures 3(b)-3(e)mentioning

confidence: 99%

“…Most of generations of vector beams directly from a laser cavity have been devoted to vector Laguerre-Gaussian beams [1,[11][12][13][14]]. An axicon, or special optical elements were used to convert a linearly polarized Gaussian beam to a vector non-diffracting beam [15][16][17][18].…”

mentioning

confidence: 99%

Generation of radially polarized Bessel–Gaussian beams from c-cut Nd:YVO_4 laser

2014

View full text Add to dashboard Cite

We experimentally demonstrate the generation of radially polarized Bessel-Gaussian beams from a c-cut Nd:YVO₄ laser with a hemispherical cavity configuration by proper mode control. The output beam has an annular-shaped intensity distribution with radial polarization. When the beam is focused, the intensity pattern changes to a multi-ring, which is a typical characteristic of the lowest transverse mode of vector Bessel-Gaussian beam. Higher-order modes of vector Bessel-Gaussian beam are also observed from the same cavity by slightly changing the cavity alignment. The experimental results show a good agreement with the simulation results for both focal and far fields. The present method is a simple and direct way for generating vector Bessel-Gaussian beams.

show abstract

“…The gain medium is typically a fraction of a millimeter in thickness and the thermal lens of the material ensures a stable cavity configuration. 22,23 Cylindrical vector beams have been produced previously in custom (bulk) laser resonators [24][25][26][27][28][29][30][31][32] and in non-MMLs [33][34][35] where, in the case of the latter, Cr 4þ ∶YAG saturable absorbers together with custom axisymmetric subwavelength gratings as the output coupler have been used for mode selection. In general, the laser beam generated by an MML is Gaussian in shape, and actively selecting other transverse modes is not a trivial task; due to the compact design of the microchip laser such mode selection cannot be achieved by the standard method of insertion of intracavity optical elements.…”

Section: Introductionmentioning

confidence: 99%

Radially polarized cylindrical vector beams from a monolithic microchip laser

et al. 2015

View full text Add to dashboard Cite

Monolithic microchip lasers consist of a thin slice of laser crystal where the cavity mirrors are deposited directly onto the end faces. While this property makes such lasers very compact and robust, it prohibits the use of intracavity laser beam shaping techniques to produce complex light fields. We overcome this limitation and demonstrate the selection of complex light fields in the form of vector-vortex beams directly from a monolithic microchip laser. We employ pump reshaping and a thermal gradient across the crystal surface to control both the intensity and polarization profile of the output mode. In particular, we show laser oscillation on a superposition of Laguerre-Gaussian modes of zero radial and nonzero azimuthal index in both the scalar and vector regimes. Such complex light fields created directly from the source could find applications in fiber injection, materials processing and in simulating quantum processes.

show abstract

Generation of a radially polarized laser beam in a single microchip Nd:YVO_4 laser

Cited by 33 publications

References 16 publications

Controlled generation of higher-order Poincaré sphere beams from a laser

Controlled generation of higher-order Poincaré sphere beams from a laser

Generation of radially polarized Bessel–Gaussian beams from c-cut Nd:YVO_4 laser

Radially polarized cylindrical vector beams from a monolithic microchip laser

Contact Info

Product

Resources

About