We introduce a novel telescope consisting of a pinhole-like camera with rotatable MEMS micromirrors substituting for pinholes. The design is ideal for observations of transient luminous phenomena or fast-moving objects, such as upper atmospheric lightning and bright gamma ray bursts. The advantage of the MEMS "obscura telescope" over conventional cameras is that it is capable both of searching for events over a wide field of view, and fast zooming to allow detailed investigation of the structure of events. It is also able to track the triggering object to investigate its space-time development, and to center the interesting portion of the image on the photodetector array. We present the proposed system and the test results for the MEMS obscura telescope which has a field of view of 11.3 degrees, sixteen times zoom-in and tracking within 1 ms.

ZnO thin-film loading of YZ-LiNbO3 is used to suppress all the harmonic generations of surface acoustic waves (SAW’s) in the substrate. An optical probing technique is used to measure the intensity variations of the harmonics as a function of acoustic power. Only the first-order diffracted light intensity is observed owing to the suppression of higher harmonic generations of SAW’s. This linearization of the first-order diffracted light intensity versus acoustic power is found to be independent of the interaction length (up to 5 mm) and the acoustic power (up to 4.3 W). The attenuation of SAW’s on YZ-LiNbO3 with a 2-μm ZnO layer was measured to be about 5 dB/cm at 325 MHz.