Mixed Injection Femtosecond Optical Parametric Amplification Technology Research

Based on stable and reliable solid-state lasers and amplifiers which have been greatly developed so far, optical parametric amplification has become a routine process in obtaining tunable ultrafast lasers. We study on this nonlinear optical process and present a novel hybrid seeded optical parametric amplifier (OPA). Hybrid seeding is first adopted in an external narrow-band laser seeded mid-infrared OPA to ensure spectrally clean signal pulses with no seeding background, while the OPA remaining to be compact and efficient. Hybrid seeding is also found able to gain control on phase transferring during an OPA process. We theoretically and experimentally verified that the signal phase can be restored to a great extent with a hybrid seeding scheme, regardless of how distorted a phase the pump carries. In this way, signal beam with fine temporal and spacial quality can be obtained regardless of a distorted pump beam, thus promising in high power optical parametric chirped pulse amplification (OPCPA). The hybrid-seeded femtosecond OPA is also applied as a source to achieve tunable narrow-band lasers, in the way that signal pulses from the femtosecond OPA are sent to a pulse stretcher with a chirp-matched mix-frequence process. The pulse stretcher, together with the femtosecond OPA, provides a way to produce synchronized and both tunable femtosecond and tens-of-picosecond narrowband pulses, an access to both high temporal and spectral resolution. This paper includes the following chapters.1. Ultrafast optics and frequency conversion.2. Ultrafast OPA theory and design.3. Hybrid seeded femtosecond OPA design.4. Phase control by hybrid seeding in a pair of OPA crystals.5. Generation of tunable narrowband pulses initiating from a femtosecond hybrid-seeded OPA.