Fiber LasersDr. Nasser Peyghambarian. High power short cavity Er and Yb doped fiber lasers as opposed to long cavity fiber lasers are being developed. There are formidable challenges in achieving high power output from a short cavity fiber laser. Much higher Er and Yb doping level in the glass host is required to efficiently absorb the pump power within a short piece of fiber. Special phosphate glasses are successfully developed in house that could accommodate very high doping levels of Er and Yb ions without significantly inducing Er ion clustering and the detrimental up-conversion process. Record high gain and power per unit length of fiber are generated from fiber lasers with several centimeter long of active fibers. In addition, other novel structures such as photonic crystals fibers, thulium doped tellurite glasses for mid IR applications are also being developed for special fiber lasers. This research is partially supported by TRIF, Arizona’s Technology & Research Initiative Funding enterprise: http://www.optics.arizona.edu/TRIF. High-power Semiconductor Laser ResearchDr. Mahmoud Fallahi. Focus of the laser research is on the development of high power single-mode surface emitting lasers with high brightness for various fiber optic and free-space applications. The research covers the design and fabrication of grating coupled tapered cavity lasers on InGaAsP/InP and InGaAs/GaAs strained multi-quantum well structures covering a wavelength range of 980 nm to 1550 nm. Another focus area is the development of high power optically pumped vertical external cavity surface emitting lasers. Photorefractive Polymer Optics LaboratoryDr. Nasser Peyghambarian. Research includes synthesis and characterization of photorefractive polymer composites that contain sensitizing agents, photoconducting polymers, nonlinear electro-optical chromophores, and plasticizers; optoelectronic systems using photorefractive thin-film devices for applications in imaging, laser communication, optical security verification, and industrial inspection. Pioneering work has been performed in this lab. One of the current goals is to use dynamic photorefractive hologram to achieve real-time, low-cost, all-optical adaptive correction of phase distortion for high-performance laser communication link. Another research direction is to employ the dynamic hologram for fast, parallel imaging of biomedical tissues. Correspondingly, the focus of the material research is to develop novel composites working at optical communication wavelength of 1550 nm and other near infrared wavelengths that have low absorption, low dispersion, and low scattering for biomedical samples. The general requirements on the materials are good stability, high sensitivity, fast response, and high diffraction efficiency. This research is partially supported by TRIF, Arizona’s Technology & Research Initiative Funding enterprise: http://www.optics.arizona.edu/TRIF. |