Unformatted text preview: Homework #1 Laser Test Light Collection Efficiency To quantify the injection efficiency of laser diodes, it is important to know how much of the total emitted light is collected by the measurement system. This becomes complicated, because the lasers are often tested with short pulses, and large photodiodes have too slow a temporal response to monitor the light pulse. Your task is to optimize the light collection efficiency. The experimental 405nm lasers emit light with an angular distribution identical to the Nichia NDHV220APA laser shown in the attached specification sheet. The lasers will be tested with 10ns pulses, so the photodiode response must be at least this fast. Your supervisor has selected the Hamamatsu S3072 photodiode in the attached specification sheet, with an active diameter of 3 mm. Answer the following questions, showing your calculations and justifying any assumptions that you make. 1. What fraction of the emitted light can be collected by the photodiode without any intervening components? 2. Design an optical system to improve this, using any components available from CVI Melles Griot or Newport Corporation. Include the part number and relevant parameters. How much of the total light will your design collect? 3. Discuss any problems or limitations that remain. Materials 288S Spring 2010 ...
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This note was uploaded on 02/02/2011 for the course ECE 227A taught by Professor Coldren during the Spring '08 term at UCSB.
- Spring '08