There is a growing demand for MHz-repetition rate industrial ultrafast laser sources that operate from the ultraviolet to the near IR. This paper discusses third harmonic generation (THG) of a high repetition-rate, femtosecond dual function Yb:YAG thin slab amplifier. Both pre-amplifier and power amplifier functions take place in a single crystal and homogeneous pumping of the thin slab is achieved by means of novel diode bar imaging. Fundamental output powers of <130 W at a wavelength of 1030 nm are maintained across a range of pulse repetition frequencies from 1 MHz to 40 MHz with a pulse duration of 900 ± 100 fs and M2 ~ 1.2. Second harmonic generation (SHG) at 515 nm with a conversion efficiency of 76% with respect to the incident fundamental is achieved using type-1 critically phase-matched LBO resulting in average powers of <90 W, a pulse energy of <90 µJ, with an M2< 1.2 and pulse durations of 800 ± 100 fs. The fundamental and second harmonic outputs were frequency mixed in a critically phase matched LBO crystal to produce third harmonic generation (THG) at 343 nm. Several lengths of type-2 THG LBO were investigated alongside type-1 THG LBO, with <50 W of UV produced at single-pass conversion efficiencies of <40% with respect to incident fundamental power at the SHG stage, corresponding to pulse energies of <50 µJ. Beam quality and pulse durations at 343 nm were investigated across 1–40 MHz.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.