An injection modelocked Ti-sapphire laser for synchronous photoinjection

Conference · Tue Jul 01 04:00:00 EDT 1997

OSTI ID:505404

Hovater, C; Poelker, M

The CEBAF 4 GeV accelerator has recently begun delivering spin-polarized electrons for nuclear physics experiments. Spin-polarized electrons are emitted from a GaAs photocathode that is illuminated with pulsed laser light from a diode laser system synchronized to the injector chopping frequency (499 MHz). The present diode laser system is compact, reliable and relatively maintenance-free; however, output power is limited to less than 500 mW. In an effort to obtain higher average power and thereby prolong the effective operating lifetime of the source, they have constructed an injection modelocked Ti-sapphire laser with picosecond pulsewidths and gigahertz repetition rates. Modelocked operation is obtained through gain modulation within the Ti-sapphire crystal as a result of injection seeding with a gain-switched diode laser. Unlike conventional modelocked lasers, the pulse repetition rate of this laser can be discretely varied by setting the seed laser repetition rate equal to multiples of the Ti-sapphire laser cavity fundamental frequency. They observe pulse repetition rates from 223 MHz (fundamental) to 1,560 MHz (seventh harmonic) with average output power of 700 mW for all repetition rates. Pulsewidths ranged from 21 to 39 ps (FWHM) under various pump laser conditions.

• Research Organization: Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
• Sponsoring Organization: USDOE Office of Energy Research, Washington, DC (United States)
• DOE Contract Number: AC05-84ER40150
• OSTI ID: 505404
• Report Number(s): DOE/ER/40150--1148; JLAB-ACT--97-06; CONF-970503--164; ON: DE97006860
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
BEAM INJECTION
CEBAF ACCELERATOR
ELECTRON BEAMS
ELECTRON SOURCES
MODE LOCKING
POLARIZED BEAMS
SOLID STATE LASERS