A High Power, Frequency Tunable Colloidal Quantum Dot (CdSe/ZnS) Laser.
Tunable lasers are essential for medical, engineering and basic science research studies. Most conventional solid-state lasers are capable of producing a few million laser shots, but limited to specific wavelengths, which are bulky and very expensive. Dye lasers are continuously tunable, but exhibit very poor chemical stability. As new tunable, efficient lasers are always in demand, one such laser is designed with various sized CdSe/ZnS quantum dots. They were used as a colloid in tetrahydrofuran to produce a fluorescent broadband emission from 520 nm to 630 nm. The second (532 nm) and/or third harmonic (355 nm) of the Nd:YAG laser (10 ns, 10 Hz) were used together as the pump source. In this study, different sized quantum dots were independently optically pumped to produce amplified spontaneous emission (ASE) with 4 nm to 7 nm of full width at half-maximum (FWHM), when the pump power and focusing were carefully optimized. The beam was directional with a 7 mrad divergence. Subsequently, these quantum dots were combined together, and the solution was placed in a resonator cavity to obtain a laser with a spectral width of 1 nm and tunable from 510 to 630 nm, with a conversion efficiency of about 0.1%.
Research Chair on laser diagnosis of cancers, College of Science, King Saud University, 11451, Riyadh, Saudi Arabia. deva230@yahoo.com.|Department of Physics and Astronomy, College of Science, King Saud University, 11451, Riyadh, Saudi Arabia. deva230@yahoo.com.|Department of Electrical and Electronics, College of Engineering, Kalasalingam University, Anand Nagar, Krishnankoil, Virudhunagar 626190, Tamil Nadu, India. deva230@yahoo.com.
Saradh
S
Prasad
Research Chair on laser diagnosis of cancers, College of Science, King Saud University, 11451, Riyadh, Saudi Arabia. hanan-laser@hotmail.com.
Hanan Saleh
HS
AlHesseny
Research Chair on laser diagnosis of cancers, College of Science, King Saud University, 11451, Riyadh, Saudi Arabia. malsalhi@ksu.edu.sa.|Department of Physics and Astronomy, College of Science, King Saud University, 11451, Riyadh, Saudi Arabia. malsalhi@ksu.edu.sa.
Mohamad S
MS
AlSalhi
Department of Electrical and Electronics, College of Engineering, Kalasalingam University, Anand Nagar, Krishnankoil, Virudhunagar 626190, Tamil Nadu, India. deva230@yahoo.com.
Durairaj
D
Devaraj
Research Chair on laser diagnosis of cancers, College of Science, King Saud University, 11451, Riyadh, Saudi Arabia. mvadivel@ksu.edu.sa.|Department of Physics and Astronomy, College of Science, King Saud University, 11451, Riyadh, Saudi Arabia. mvadivel@ksu.edu.sa.
Vadivel
V
Masilamai
amplified spontaneous emission; broad tunable laser from 520 to 630 nm.; quantum dots CdSe/ZnS; spectral properties