Self Frequency-doubled Nd-doped YCOB Laser

Neodymium-doped yttrium calcium oxyborate (Nd:YCOB) is the single active gain element for a solid-state laser device capable of achieving both lasing and self-frequency doubling optical effects. A pumping source for optically pumping Nd:YCOB can generate a laser light output of approximately 400 mW at approximately 1060 nm wavelength and a self-frequency doubled output of approximately 60 mW at approximately 530 nm wavelength. Thus, a laser device can be designed that is compact, less expensive and a high-powered source of visible, green laser light

Yb-Doped: YCOB Laser (DIV)

A tunable, solid state laser device with both visible and infrared laser emission is developed with a trivalent ytterbium-doped yttrium calcium oxyborate crystal as the host crystal. The Yb:YCOB crystal generates an infrared fundamental light over a wide bandwidth, from approximately 980 nanometers (nm) to approximately 1100 nm. The bandwidth generated by the Yb:YCOB crystal is approximately 100 nm wide and supports the generation of pulsed infrared light or when self-frequency doubled provides a compact, efficient, source of tunable, visible, blue or green laser light in wavelengths of approximately 490 nm to approximately 550 nm

Implementing The Prison Rape Elimination Act: A Toolkit for Jails

Minor edits. “The goal of this Toolkit is to provide jails of all sizes, political divisions, and geographic locations with a step-by-step guide for preventing, detecting, and eliminating sexual abuse of inmates in their custody – and for responding effectively to abuse when it occurs. Prison rape includes all forms of inmate sexual abuse within a correctional facility, including state and federal prisons, county and municipal jails, police lock-ups, holding facilities, inmate transportation vehicles, juvenile detention facilities, and community corrections facilities. Protecting arrestees, detainees, and inmates from sexual violence is part of a jail’s core mission. This toolkit will help assess your jail’s operations with an eye to improvements.” The Toolkit is divided into folders holding materials related to: introductory information about PREA [Prison Rape Elimination Act] and it Standards; a Self-Assessment Checklist with supporting forms “to provide a step-by-step process for jails to review and assess policies, procedures, and practices in light of the PREA Standards and accepted best practices”; and additional resources to assist you in PREA-readiness

Ycob Lasers

We review new developments with a new laser host material, YCa4O(BO3)3 or YCOB. Lasers based on this host material will open new opportunities for the development of compact, high-power, frequency-agile visible and near IR laser sources, as well as ultrashort-pulse sources. Efficient diode-pumped laser action with both Nd-doped and Yb-doped YCOB has already been demonstrated. Moreover, since these materials are biaxial and have high nonlinear optical coefficients, they have become the first laser materials available as efficient self-frequency-doubled lasers capable of providing tunable laser emission in several regions of the visible spectrum. Self-frequency doubling eliminates the need for inclusion of a nonlinear optical element within or external to the laser resonator. These laser materials possess excellent thermal and optical properties, have high laser-damage thresholds, and can be grown to large sizes. In addition they are non-hygroscopic. They, therefore, possess all the characteristics necessary for laser materials required in rugged, compact systems. Here, we summarize the rapid progress made in the development of this new class of lasers and review their potential for a number of applications

Improved Second-Harmonic Generation By Selective Yb Ion Doping In A New Nonlinear Optical Crystal Yca4O(Bo3)3

We describe experiments characterizing a new nonlinear optical crystal, YCa4O(BO3)3 (YCOB). This crystal has a number of advantages over other commonly available nonlinear optical crystals. It has a higher nonlinear coefficient than KDP, can be fabricated to large sizes (approximately 3-in diameter, 8-in length), and has a high damage threshold. Moreover, this new nonlinear optical crystal is nonhygroscopic, has good optical quality and mechanical properties, allowing easy optical polishing. This crystal, YCa4O(BO3)3, commonly termed YCOB, is one of a family of new nonlinear crystals, the oxyborates, that include RECa4O(BO3)3 (RE = La3+, Lu3+, Y3+, Sm3+, Gd3+, Er3+, and Nd3+). In this paper, we also successfully demonstrate a technique for improving the nonlinear optical properties of this crystal. This technique, ion substitution, has hetertofore had limited success with other crystal hosts. However, the inclusion of yttrium in YCOB provides the opportunity to exploit this technique. Yb3+, which has larger mass, but approximately the same atomic size as Yb3+, can be substituted into the crystal structure without introducing stress and nonuniformities. A systematic investigation of the linear and nonlinear characteristics of several crystals doped with various levels of Yb demonstrate that selective substitution of Yb in YCa4O(BO3)3 improves the second-harmonic conversion efficiency by increasing the optical nonlinearity

Laser Action In Yb\u3csup\u3e3+\u3c/sup\u3e:Ycob (Yb\u3csup\u3e3+\u3c/sup\u3e:Yca4O(Bo3)3)

Progress in the growth of the rare earth calcium oxyborate crystals has now generated a new class of laser materials that can be used as both a laser host and a nonlinear frequency converter. Laser action and self-frequency doubling (SFD) has been observed with both 10% and 20% Yb3+-doped YCOB crystals. Laser operation was obtained in a hemispherical linear cavity, end-pumped with a tunable cw Ti:Sapphire or a 980 nm laser diode pump source. Under Ti:Sapphire pumping at 900 nm, an output power of 230 mW and a slope efficiency of 29% was obtained using the 10% doped sample. Laser action was seen at 1050 nm. Laser operation of the 20% sample had a maximum output power of approximately 300 mW with a slope efficiency of 35.8% at 1088 nm. Laser action was not obtained at the peak of the fluorescence emission (approximately 1030 nm) in this crystal as a consequence of self-absorption on the short-wavelength side of the emission band. Diode-pumped operation at the narrow absorption peak of 977 nm was achieved and early results show an improved slope efficiency of 34% in comparison to the 10% doped crystal under Ti:Sapphire pumping. We have also observed self-frequency doubling in Yb3+:YCOB. The 20% Yb3+:YCOB crystal used for this test was cut with a phase-matching angle of 36.22°. The self-frequency doubling efficiency was low due to the absence of any frequency selective elements in the cavity to narrow the linewidth of the fundamental emission. The SFD emission occurred at 543 nm

Scaling Of Longitudinally Diode-Pumped Self-Frequency-Doubling Nd:Ycob Lasers

We report the scaling of a new self-frequency-doubling laser, based on the crystal Nd3+:YCa4O(BO3)3, to higher powers. The power scaling is achieved by diode pumping using a novel technology of combining the output of up to four high-brightness laser diodes. Spectroscopic, thermo-mechanical, and laser properties are investigated for use in designing high-power self-frequency-doubling lasers. Using a method of angular-multiplexing individual laser diodes for pumping, we demonstrate output powers of more than 1.9 W of fundamental (1060 nm) radiation and 245 mW at the second harmonic. Experimental investigation rendered a thermal stress resistance figure-of-merit for this material to be between 210-280 W/m

Self Frequency Doubled Nd-Doped YCOB Laser

Neodymium-doped yttrium calcium oxyborate (Nd:YCOB) is the single active gain element for a solid-state laser device capable of achieving both lasing and self-frequency doubling optical effects. A pumping source for optically pumping Nd:YCOB can generate a laser light output of approximately 400 mW at approximately 1060 nm wavelength and a self-frequency doubled output of approximately 60 mW at approximately 530 nm wavelength. Thus, a laser device can be designed that is compact, less expensive and a high-powered source of visible, green laser light