Diode pumping of a solid-state laser rod by a two-dimensional CPC–elliptical cavity with intervening optics

Abstract

The pump radiation from a large area two-dimensional diode stack is concentrated into a cylindrical intervening optics by a first-stage 2D-CPC concentrator. The compressed radiation from the intervening optics is then efficiently coupled into a laser rod by a second-stage 2D-elliptical pump cavity. Depending on the width of the pump source, optimized rod mounting position is found through a non-sequential ray-tracing analysis. By comparing with the performance of a 2D-CPC-CPC cavity, significant improvements in both absorption efficiency and absorption distribution are achieved by a 2D-CPC-EL cavity. This asymmetric pumping scheme constitutes also an effective alternative to conventional symmetric pumping approaches.

Construction of an array of LEDs coupled to a concentrator for phototherapy

“…This non-imaging optical system converts the radiations from a large-area homogenous source emitting uniformly into small angles, to a small-area homogenous output light distribution emitting into large angles. This implies that irradiance is larger at the concentrator output end than at its entrance aperture, leading to a net light concentration 11 and uniformity, not attainable by conventional LED devices with image-forming system. Contrary to non-imaging devices, whose main goal is the maximum flux at the output end, image-forming systems such as optical lenses do not perform well as concentrators 12,13 .…”

An alternative solar pumping approach by a light guide assembly elliptical-cylindrical cavity

“…4. This cylindrical lens enhances the light concentration within the central core region of the crystal rod [21]. For the flow tube of 8 mm internal diameter and laser rod of 5 mm diameter, the cylindrical intervening optics has 6.4 mm width, 2.5 mm thickness, 3.7 mm front surface curvature, À10 mm rear surface curvature and 60 mm extrusion length.…”

A review on the recent research progress in the compound parabolic concentrator (CPC) for solar energy applications

“…The basic of CPC is still as the same as it was designed at the beginning, but researchers have spared no effort to investigate its optic performance and applications in much more disciplines in these years. The rest of applications are in quite various areas, such as gas sensing system [17], wireless communication system [18], infrared temperature sensor system [19], solar thermal water splitting system [20], sky radiator [21], photodiode [22], lasers [23] [24], LED projector [25] [26] [27], terahertz technology [28] [29] and overmoded waveguide [30]; CPC does not play critical roles in these applications usually. In the aspect of solar energy, there are a lot of review articles on CPV/CPVT technology [31][32][33][34][35] and solar thermal technology [35][36][37][38][39][40] that refer to CPC as one of the practical solution in those areas.…”