Improved 2nd harmonic rise-time in a thermal-lens-dominated extended-cavity micro-laser
Many commercially available compact, micro-cavity diode-pumped solid-state lasers achieve a stable resonator condition following the formation of an intra-cavity thermal lens. Typically, this thermal lens forms as a result of localized thermal expansion in the host material due to the very high optical power of the infrared pump beam. Additionally, most common DPSS host media, such as Nd:YAG and Nd:YVO4 exhibit high dn/dT, change in refractive index with temperature. Thermal lens formation time dominates stable resonator establishment and, thus, the rise-time of the intra-cavity-generated visible second-harmonic output light. Thermal lens formation time may range from 10's of microseconds to several milliseconds, depending on pump power, the host material dn/dT, and the volume and length of the host material. This paper describes a unique approach that improves the second-harmonic rise-time - and, thus, the modulation bandwidth - for high-power VECSELs by several orders of magnitude. This approach, while typically used in some laser systems for other purposes, allows direct modulation of high-power VECSELs to greater than 100 megahertz with second-harmonic rise-time of a few nanoseconds.
RGB Laser Light Sources for Projection Displays
We report on high power RGB laser light sources made from vertically-emitting intracavity-doubled lasers. The novel light sources open the door to a completely new viewing experience of digital display content.
Microwave source with enhanced radiation power based on orbitron MASERs
We have proposed the design of high power microwave source in a vacuum tube based on the theory of negative mass instability. The proposed source does not operate based on a slow-wave structure but instead makes use of accelerated charged particles. In our structure, an electron emitter injects the charged particles into to the cavity. Emitted particles move around the anode, which leads to electron acceleration and emission of electromagnetic waves with a specific frequency. In this paper, we have enhanced the output power and frequency of microwave source by variation of particles initial energy and the number of anodes incorporating their specific arrangement and applied voltages. Working at room temperature, compactness, wide bandwidth, and tunability of output frequency are among the advantages of the proposed source.