OPTICAL DEVICE HAVING PHASE-LOCKED DIODE LASER ARRAY

摘要

PURPOSE: To obtain a radiation spot of the diffraction threshold having decreased aberrations and to compactify a device by arranging a prism system consisting of at least one prisms and a space filter in this order behind a collimating lens. CONSTITUTION: The synthesized radiation beam (b) released from a diode laser array 10 is collimated at a sectional plane but is curved at a lateral plane in the collimating lens 17. The beam is not affected at the sectional plane but refraction occurs to spread the beam dependent upon an angle α on an incident end face 23 at the lateral plane in the prism 20. A diaphragm 19 is arranged behind the same and its opening and the orientation and parameter of the prism 20 are so determined that the diaphragm 19 acts to allow the passage of only the radiation pattern 10 and to block all of the side lobes 11 , 12 , etc. The spot V of the diffraction threshold having the min. size is obtd. from the objective lens 18 and the shape thereof is rounded. The astigmatism of the array 10 is compensated by the astigmatism from the prism 20.