High power and high repetition Nd:YAG laser pumped by cw LDs

Author

Fujita, H. ; Nakatsuka, M. ; Mitra, A. ; Wang, T. ; Tsubakimoto, K. ; Fijimoto, Y. ; Yoshida, H. ; Miyanaga, N. ; Izawa, Y. ; Matsuoka, S. ; Kubomura, H. ; Kasamatsu, T. ; Uchiyama, T. ; Miyajima, H. ; Kan, H.

Author_Institution

Inst. of Laser Eng., Osaka Univ., Japan

fYear

2005

fDate

12-17 June 2005

Firstpage

74

Abstract

We have been developing a high repetition (5 kHz) and high power (5 kW) Nd:YAG laser system for EUV lithography. Key subjects are (1) reliable front-end, (2) uniform and high density pumping of main amplifier rods, and (3) compensation of thermal effects. Fairly good uniformity was achieved by adjusting pumping geometry. Detail system analysis suggests that 8 amplifier modules pumped at 24.0 kW power are required to get output of 5 kW under relatively small thermal effects.

Keywords

compensation; laser beams; neodymium; optical pumping; solid lasers; thermal lensing; 24.0 kW; 5 kW; EUV lithography; Nd:YAG laser; YAG:Nd; YAl5O12:Nd; amplifier rods; cw LD pumping; density pumping; pumping geometry; reliable front-end; thermal effects compensation; Diode lasers; Fiber lasers; Laser excitation; Laser modes; Power amplifiers; Power lasers; Power system reliability; Pulse amplifiers; Pulse modulation; Pump lasers;

fLanguage

English

Publisher

ieee

Conference_Titel

Lasers and Electro-Optics Europe, 2005. CLEO/Europe. 2005 Conference on

Print_ISBN

0-7803-8974-3

Type

conf

DOI

10.1109/CLEOE.2005.1567863

Filename

1567863