Some reach-through avalanche photodiodes are found to exhibit anomalous oscillations when illuminated by high-level optical power. Experimental study of the phenomena shows that the anomalous oscillation occurs below a voltage at which the depletion layer begins to extend into the layer. Some relations of oscillation frequency with biasing voltage, optical power density incident on the photosensitive area, and diode parameters are also described. These results should prove useful in the design of a reach-through avalanche photodiode free from anomalous oscillations.
Knowledge of the baseband frequency responses of optical components is prerequisite to the design of optical fiber transmission systems. The sweep-frequency method is effective for obtaining frequency responses because of its large SNR. However, the use of GaAs lasers as optical signal sources involves several problems such as resonances below 1 GHz and spectrum broadening. In order to overcome these problems, a single transverse mode GaAs laser called a buried heterostructure GaAs laser was employed as an optical signal source in the sweep-frequency measurement system. This measurement system has a wideband flat sweep-frequency range of 0.5-1300 MHz as well as a wide dynamic range of more than 60 dB at optical levels.
This paper introduces an example of engineer training conducted in a factorywhere telecommunication systems and related products are developed and manufactured. About 1,400 engineers are being trained There are seven specialty categories according to the types of duties of the engineers. Guidelines are prepared for these engineering specialty categories to promote well-planned training of engineers. The guidelines are posted on the factory's intranet to invite trainees and to accept their applications.The training management system stores the individual engineer's training history and .future plans in a database based on the trainee's program. A person in charge is assigned to each engineering category to systematically establish new training courses, close obsolete courses, integrate courses, or imprave a course's curriculum.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.