We present results from a theoretical model that has been developed to simulate the 3-micrometer laser transition in Er3+ doped Y 3Al5O12 (YAG), Y2Sc 2Ga3O12 (YSGG), LiYF4 (YLF) and BaY2F8 (BaYF) host crystals. The ra...
详细信息
Distributed feedback (DFB) lasers are used extensively as optical sources within fiber optic telecommunications systems. These semiconductor lasers are valued for their single optical mode operation which enables thei...
详细信息
ISBN:
(纸本)0819420670
Distributed feedback (DFB) lasers are used extensively as optical sources within fiber optic telecommunications systems. These semiconductor lasers are valued for their single optical mode operation which enables their use in high bit rate digital and broadband analog transmission systems. We discuss requirements imposed upon DFB lasers used in such applications. We briefly review and illustrate general techniques for modeling DFB laser operation by comparison of measured and modeled device characteristics below and above lasing threshold. We focus on the phenomenon of spatial hole burning which substantially affects operation of all DFB lasers, especially those tailored to produce high fiber coupled power from a single mirror facet. We illustrate insights gained by measurement and modeling of DFB lasers using as an example the particular case of analog transmission of multichannel video signals.
Efficient lasing on multiple-selected lines has been recently demonstrated experimentally on a CW HF chemical laser. Multiple-selected-line operation is required to both enhance atmospheric transmission, and to ensure...
详细信息
The purpose of this study is to demonstrate that topographic irregularities in the form of central islands of higher refractive power can be seen following excimer laser refractive surgery. We reviewed the computerize...
详细信息
ISBN:
(纸本)0819414190
The purpose of this study is to demonstrate that topographic irregularities in the form of central islands of higher refractive power can be seen following excimer laser refractive surgery. We reviewed the computerized corneal topographic maps of 35 patients undergoing excimer laser PRK for compound myopic astigmatism or anisometropia from 8/91 to 8/93 at the USC/Doheny Eye Institute. The topographic maps were generated by the Computed Anatomy Corneal modeling System, and central islands were defined as topographic areas of steepening of at least 3 diopters and 3 mm in diameter. A grading system was developed based on the presence of central islands during the postoperative period. Visually significant topographic steep central islands may be seen in over 50% of patients at 1 month following excimer laser PRK, and persist at 3 months in up to 24% of patients without nitrogen gas blowing. Loss of best corrected visual acuity or ghosting is associated with island formation, and may prolong visual rehabilitation after excimer laser PRK.
暂无评论