Related Experiment Video
Updated: Jan 22, 2026

Endoscopy Guided Photoablation of Endometrial Cysts using a 980 nm Laser with a Contact Fiber in Mares
Published on: July 16, 2020
626-nm single-frequency semiconductor laser system operated near room temperature for mW-level second-harmonic
1Space-Time Engineering Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
Abstract:
We report a 626-nm, single-frequency generation based on laser diodes operated near room temperature and the second-harmonic generation with an output power of 2 mW at 313 nm. A fundamental single-frequency laser at 626 nm consists of an external-cavity diode laser and a tapered semiconductor amplifier with 200 mW output. Antireflection coating of the laser diode expands the wavelength tuning range and realizes single-frequency output at 626 nm at room temperature. 313 nm light is generated by cavity-enhanced frequency doubling with a β-BaB2O4 crystal. A 313 nm laser with mW-level output power is useful for various experiments using laser cooling of beryllium ions.
Related Concept Videos
Harmonic Mean
Take the example of the speed of a car, which is the measure of the rate of distance traveled. If the vehicle traverses the same distance back-and-forth, its average speed equals the total distance traveled divided by the total time taken. However, if the car moves with varying speeds, then the arithmetic mean is more skewed...
Semiconductors
Metals such as copper (Cu), zinc (Zn), or lead (Pb) have low resistivity and feature conduction bands that are either not fully occupied or overlap with the valence band, making a bandgap non-existent. This allows electrons in the highest energy levels of the valence band to easily transition to the conduction band upon gaining...
Types of Semiconductors
Metal-Semiconductor Junctions
Schottky Barriers
Schottky barriers arise when a metal with a work function (Φm) contacts a semiconductor with a different work function (Φs). Initially, electrons transfer until the Fermi levels of the metal and semiconductor align at equilibrium. For instance, if Φm > Φs, the semiconductor Fermi level is higher than the metal's before contact. The...
Energy in Simple Harmonic Motion
Simple Harmonic Motion

