A laser pumped Nd(3+)-doped YAG fiber-optic thermal tip for laser thermotherapy.
OBJECTIVE
Photo-thermal converters have been successfully used in laser surgery; however, most of the currently used converters are likely to be damaged in the operations due to various problems, preventing them from being efficiently and repeatedly used in laser thermotherapy. Aiming to solve these problems, we report a new type of fiber-optic photo-thermal converter with higher stability.


METHODS
A laser-pumped highly Nd(3+)-doped Y(3)Al(5)O(12) (YAG) crystal fiber tip had been fabricated for photo-thermal conversion by means of phonon relaxation. The 15at.% neodymium-doped near cylindrical YAG crystal fiber tip, with maximum diameter of 1.1 mm and length of 2.7 mm, was fabricated on a 1 mm-thick 42 mm-long pure YAG single crystal fiber by laser heated pedestal growth (LHPG) method.


CONCLUSIONS
Pumping by a Ti:Sapphire laser with central wavelength of 805 nm, the tip generated a temperature rise of 15 degrees C in egg white with pumping power of 710 mW, the tip temperature increased approximately linearly with the increased pumping power. The distribution of the temperature in two media had also been measured. Experimental results indicated that the tip was promising for laser thermotherapy applications.
Tong
Limin
L
Division of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA. ltong@fas.harvard.edu
Zhu
Dan
D
Luo
Qingming
Q
Hong
Defei
D
D004867:Equipment Design; D005336:Fiber Optic Technology; D017075:Laser Coagulation / Q000295:instrumentation*; D053685:Laser Therapy / Q000295:instrumentation*; D055100:Optical Fibers; D013696:Temperature