Diode-Laser Phase Conjugation 03-FS-030 Final Report | |
Page, R H ; Beach, R J ; Payne, S A ; Holzrichter, J F | |
Lawrence Livermore National Laboratory | |
关键词: Lawrence Livermore National Laboratory; 75 Condensed Matter Physics, Superconductivity And Superfluidity; Solid State Lasers; 42 Engineering; 71 Classical And Quantum Mechanics, General Physics; | |
DOI : 10.2172/15014618 RP-ID : UCRL-TR-209700 RP-ID : W-7405-ENG-48 RP-ID : 15014618 |
|
美国|英语 | |
来源: UNT Digital Library | |
【 摘 要 】
Arrays of lasers are often considered when a need exists to increase laser optical output power, for a variety of purposes. Similarly, individual semiconductor laser-diodes, generating 0.01-1.0 W each, are commonly placed in arrays in order to increase total optical power onto targeted objects. Examples of such usage are diode-laser pump arrays for solid-slab heat-capacity lasers, laser arrays for heat-treating materials, and arrays for efficient solid state laser systems. The commercial and defense communities also use such arrays for many applications from laser range-finders, laser designators, to laser machining systems, etc. However, the arraying process does not automatically increase ''focusable'' light on target (i.e., intensity/steradian). For those applications requiring the highest focusability, it is necessary that the collective output beam from arrays of individual lasers be phase-coherent. Under this condition, the individual laser-element optical outputs are ''fused together'' into a larger area, phase coherent (i.e., all wavefronts are ''in step''), high-power combined beam. The process of joining multiple laser beams together to produce a single coherent wave, is in general very difficult and seldom accomplished. Thus joining together many hundreds to thousands of beams from individual laser-diodes, in large arrays, is still an unsolved problem. There are 2 major reasons for this. Firstly, the phase of each output laser beam (i.e. the wave-fronts) from each laser diode often fluctuates within nanosecond time periods, making a control loop with sufficient bandwidth difficult to build. In fact, phase fluctuations (related to laser linewidth) limit the size of an extended system of arrayed diodes because of speed-of-light restrictions on information flow. Secondly, the output power per prior laser diode has been low ( < 1W,) so that the size, expense, and complexity of control systems for correcting a multitude of output phases of the individual diode lasers in a large array, become prohibitive. Recently, we have been considering ways to use new diode geometries and 4-wave mixing/phase-conjugation technologies to enable large arrays of semiconductor lasers to be phased together to produce large-output-power laser systems, with good beam quality. If the ideas hold up, arrays of 100 to > 1 million laser elements might produce 100 W to > 1 Megawatt laser beams. Such systems can have many defense and commercial applications.
【 预 览 】
Files | Size | Format | View |
---|---|---|---|
15014618.pdf | 212KB | download |