High efficiency TEM00 diode end-pumped Alexandrite laser

Flexible lasers with the ability to operate over a wide wavelength range and in various pulsing modes (CW/ps/fs) are sought after for many application areas including remote sensing and bio-photonics [1,2]. Ti:Sapphire is a well developed tunable CW and fs laser source [3] but can be bulky, inefficient and expensive due to the complex green pumping source it requires. The development of a more compact, higher efficiency, lower cost alternative would be a major advancement. The Alexandrite (Cr-doped chrysoberyl) laser shows promise for this purpose due to favourable red-diode-pumping potential and excellent lasing properties (e.g. upper-state lifetime 100x longer than Ti:sapphire). Alexandrite, developed in the 1970s, was the world’s first room temperature vibronic, broadly tunable laser but has operated mainly with flashlamp-pumping owing to the immaturity of red laser diode technology (low power, low reliability). In this work we show the use of improved red diode technology to generate highly efficient CW laser operation in an end-pumped Alexandrite laser.