title: Direct generation of 81 nJ pulses and external compression to a subpicosecond regime with a 4.9 MHz chirped-pulse multipass-cavity Cr⁴⁺:forsterite oscillator.
abstract: We report direct generation of 81 nJ chirped pulses from a room-temperature, Kerr lens mode-locked Cr⁴⁺:forsterite oscillator operating at 1258 nm. To increase the pulse energy, the pulse repetition rate of the short x-type resonator was lowered from 143 to 4.9 MHz by the addition of a q-preserving multipass cavity, which provided an additional effective optical path length of 59.4 m. The duration of the chirped pulses was around 5.5 ps with a spectral width of 21 nm. The pulses were externally compressed to 607 fs by using a diffraction grating pair. To our knowledge, this is the highest reported pulse energy directly generated from a room-temperature mode-locked Cr⁴⁺:forsterite laser.
authors.affiliation: Laser Research Laboratory, Department of Physics, Koç University Rumelifeneri, Sariyer, Istanbul, 34450, Turkey.
authors.forename: Huseyin
authors.initials: H
authors.lastname: Cankaya
authors.forename: Selcuk
authors.initials: S
authors.lastname: Akturk
authors.forename: Alphan
authors.initials: A
authors.lastname: Sennaroglu