Abstract:
An optical reflection element includes a mirror portion and an oscillator coupled to the mirror portion. The oscillator includes a base, an insulating layer, a drive element, and a monitor element. The insulating layer is formed on the base. The drive element and the monitor element are formed on the insulating layer, and are separated from each other by a separation groove. Each of the drive element and the monitor element includes a lower electrode layer, a piezoelectric layer, and an upper electrode layer formed in that order on the insulating layer. The monitor element has high detection accuracy, allowing the optical reflection element to perform self-excited driving with high accuracy.
Abstract:
A method of controlling a spectroscopic module that includes a measurement light source, a variable-wavelength optical filter, a photodiode, and a conversion circuit for converting a drive signal voltage into a gap displacement amount. The spectroscopic module has a reference light source for emitting a reference light beam of a known wavelength. The controlling method involves varying a gap for the incident reference light beam, extracting two maximum points among data output from the photodiode, and updating a first conversion formula provided in the conversion circuit through use of drive signal voltages and gap amounts corresponding to the two points.