| abstract |
(57) [Abstract] [Purpose] The etching surface is made smooth, and second exposure is performed from the etching surface to enable three-dimensional processing. [Structure] As a first exposure step, an excimer laser oscillator is arranged above the photosensitive glass plate 10 and a surface of the photosensitive glass plate 10a is irradiated with XeCl excimer laser through an exposure mask. As the laser, a pulse oscillation control type laser including the sensitivity wavelength range of photosensitive glass is used, and the energy intensity per pulse of the laser is 80 mJ / cm 2 , Irradiation was performed for about 2 pulses, and the total exposure amount was about 160 mJ / cm 2 . This is heat-treated and etched to form the groove 12. As the second exposure step, the excimer laser oscillator 3 is arranged above and the wall surface 12 of the groove 12 is inserted through the optical fiber 4. A laser is introduced into b to perform exposure to form an exposed portion 13 in the lateral direction. This is heat-treated and etched to form a groove. A three-dimensional shape of the groove portion 12 in the plate thickness direction and the groove portion in the direction perpendicular to the groove portion is formed by etching. |