Abstract
There are a number of transition metal ion lasers that are well suited as an ultrafast pulse source including Cr4+:YAG, Cr:forsterite, and Ti:sapphire lasers. However, production costs must be reduced if these lasers are to find widespread use in medical or industrial fields for such applications as THz-wave generation, multiphoton microscopy, and nonlinear Raman microscopy. Some cost-reduction will be realized by changing the pump sources of these lasers from solid-state lasers to laser diodes (LDs). With the Cr4+:YAG laser, direct LD-pumped SESAM-mode-locking has been reported using a bulk crystal emitting a 15-mW output of 62-fs pulses [1]. The aim of this research project is to improve the output of a direct LD-pumped mode-locked Cr4+:YAG laser provided with a saturable absorber. The key component is a single-crystal fiber. A fiber about 120 mm in diameter and 40 mm long has been prepared using the laser heated pedestal growth method. After crystal production, a 1-mm-thick SiO2 cladding layer is deposited. This layer can confine diffusive high-power LD light within the fiber along the entire fiber length. However, we must find a way to select the fundamental transverse oscillation mode because the fiber waveguide can support a large number of transverse modes. This research project has proposed a solution that employs the combination of the crystal fiber and an external cavity. The first femtosecond oscillation attempt with a single-crystal fiber laser was conducted with a solid-state pumping laser (Nd:YVO4 laser). The experiment was turned out to be successful as reported in [2]. The project now proceeds to a test with direct LD-pumping, and this report describes promising results.
© 2015 IEEE
PDF ArticleMore Like This
Shigeo Ishibashi and Kazunori Naganuma
ATh3A.7 Advanced Solid State Lasers (ASSL) 2013
Shigeo Ishibashi and Kazunori Naganuma
MD4 Advanced Solid State Lasers (ASSL) 2000
A. A. Lagatsky, C.T.A. Brown, W Sibbett, J.F. Allen, and W. Knox
CWA38 Conference on Lasers and Electro-Optics (CLEO:S&I) 2002