End-pumped continuous-wave passively mode-locked <inline-formula><math altimg="none" display="inline" overflow="scroll"><mrow><mi>Nd</mi><mo>:</mo><msub><mi>YVO</mi><mn>4</mn></msub></mrow></math></inline-formula> laser with low pump power

Abstract

A simple cw mode-locked solid-state laser, which is end-pumped by a low-power laser diode, was demonstrated by optimizing the laser-mode size inside the gain medium. The optimum ratio between mode and pump spot sizes inside the laser crystal was estimated for a cw mode-locked laser, taking into account the input pump power. Calculation and experiment have shown that the optimum ratio was about 3 when the pump power is 2 W, which is different from the value regularly used in passively mode-locked solid-state lasers. This conclusion is also helpful in increasing the efficiency of high-power ultrashort lasers.