Paper 11: Laser Energy Measurements by Absolute Methods
| Autor: | B. F. Scott |
|---|---|
| Rok vydání: | 1968 |
| Předmět: | |
| Zdroj: | Proceedings of the Institution of Mechanical Engineers, Conference Proceedings. 183:56-64 |
| ISSN: | 2058-3362 0367-8849 |
| DOI: | 10.1243/pime_conf_1968_183_052_02 |
| Popis: | The value of laser experiments is frequently determined by the accuracy and reliability of the techniques used for power and energy measurements. Most absolute measurements rely upon the calorimetric principle; they determine the total energy from the thermal response of a mass absorbing the radiation. Peak power is the major factor determining the design, and two distinct calorimetric groups can be identified. Pulsed solid-state lasers generate high peak powers and can create damage in the absorber unless measures are taken to restrict the specific absorption to a safe level. This is the design basis for both the cone and liquid absorption cell calorimeters. Both are widely used and can achieve an absolute accuracy of about 10 per cent. Because of the substantially lower instantaneous powers associated with continuous wave lasers surface damage is not a major problem and a variety of calorimeters, both ballistic and continuous, are admissible. Absolute accuracy, response time and convenience are the important factors determining choice. The black body absorber in the form of a sphere offers the greatest potential power range but interpretative difficulties remain to be solved. |
| Databáze: | OpenAIRE |
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