Passive Q-switching of a diode-pumped neodymium:YAG laser

Miscellaneous · Tue Jan 01 00:00:00 EST 1991

OSTI ID:7280540

Morris, J A

Compact diode-pumped neodymium:YAG lasers are becoming common commercial devices. Such lasers are often Q-switched to enhance peak power or to allow greater harmonic conversion efficiency. Active electrooptic or acoustooptic modulators are usually used to Q-switch YAG lasers. While these techniques work well, they do require expensive and bulky modulators and driving electronics. For some applications a simpler technique, such as passive Q-switching, could replace these active Q-switches. This thesis investigates the suitability of two color center materials as possible saturable absorbers for compact Nd:YAG lasers. The first material, lithium fluoride with F{sub 2}{sup {minus}} defects, has been used previously as a Q-switch for flashlamp-pumped Nd:YAG lasers. The second material, sodium chloride with F{sub 2}{sup +} defects, has not, to the author's knowledge, been used as a saturable absorber in a YAG laser. Lithium fluoride was found to be an excellent Q-switch material for a small diode-pumped YAG laser. The passively Q-switched pulses were comparable to the best results using active Q-switches. The LiF saturable absorber material is compact, inexpensive, and easy to prepare. The only discovered drawback to this material is the observation of a gradual bleaching of the saturable absorption with extended use at high peak powers. This thesis describes the properties and preparation of the LiF Q-switch material. The use of colored sodium chloride as a Q-switch material is also described. This material has the unique property that the amount of saturable loss in a particular crystal direction can be dynamically adjusted through the action of polarized light incident on the crystal.

• Research Organization: Cornell Univ., Ithaca, NY (United States)
• OSTI ID: 7280540
• Resource Relation: Other Information: Thesis (Ph.D.)
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
SOLID STATE LASERS
Q-SWITCHING
ABSORPTION
COLOR CENTERS
CRYSTAL DEFECTS
DESIGN
EFFICIENCY
LASER MATERIALS
LITHIUM FLUORIDES
NEODYMIUM LASERS
PERFORMANCE
POLARIZATION
PULSES
SATURATION
SODIUM CHLORIDES
ALKALI METAL COMPOUNDS
CHLORIDES
CHLORINE COMPOUNDS
CRYSTAL STRUCTURE
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
LASERS
LITHIUM COMPOUNDS
LITHIUM HALIDES
MATERIALS
POINT DEFECTS
SODIUM COMPOUNDS
SORPTION
VACANCIES
426002* - Engineering- Lasers & Masers- (1990-)