熱応力を利用してビームスプリッタの姿勢を受動的に制御する接着接合構造

抄録

Adhesively bonding structure for a beam splitter was proposed to offset effects of other optical elements on the position deviation of a beam spot on a photodetector with change in ambient temperature. The proposed structure has four slopes circumferentially by 90° along the upper edge of pedestal part. The thickness of outer circumferential part of the adhesive layer, which is applied between the beam splitter and the pedestal part, varies 4-fold symmetrically. This structure generates interfacial thermal stress at boundary of slopes in the tangential direction with ambient temperature change and results in tilting the beam splitter in the yaw direction. Measured results showed that a cubic glass, which was adhesively bonded to 4-fold symmetrical pedestal part of an aluminum block, was tilted as predicted. Calculated results identified that the tilt amount and direction of the beam splitter can be arranged by tuning the depth and direction of slopes.