Parametrics Generation of Intense, Widely Tunable Ultrashort Pulses in an All-Solid-State Laser System

Abstract

The generation of tunable pico- and femtosecond light pulses with parametric frequency conversion processes has attracted increased attention recently¹. New crystal materials, as BBO, LBO, and KTP, with superior nonlinearity and high damage threshold are now available, and pump lasers of improved stability allow the reliable operation of optical parametric oscillators. Parametric devices pumped either by cw modelocked lasers or by single intense ultrashort pulses have been developed. In this contribution parametric systems are discussed which are pumped by intense pulse trains of a few microseconds duration and repetition rates up to 50Hz. This technique allows the operation of widely tunable optical parametric oscillators² (OPO) and subsequent difference frequency generators³ producing tunable pulses of high peak power. The higher energy of the pump pulse trains has certain benefits for the operation of a synchronously pumped OPO, e.g., relaxed stability requirements, and the potential to work with large cavity losses (e.g. metal mirrors) allowing large tuning ranges with a single set of mirrors and high output-coupling factors for pulse shortening.