Mitutoyo Corporation

3d Innovation Co., Ltd

Hiroki Ujihara

Yoshimasa Suzuki

Shinichi Hara

Tomotaka Takahashi

Shinji Komatsuzaki

Masayuki Nara

Ryusuke Kato

A measurement apparatus including a laser apparatus that outputs a frequency-modulated laser beam with a plurality of modes of a main lobe, branch that splits the frequency-modulated laser beam into a reference light, a measurement light, and a monitor light, beat signal generator that generates a beat signal by mixing the reference light and a reflected light that is reflected by radiating the measurement light onto an object to be measured, extraction circuitry that extracts a signal component including a plurality of self-beat signals based on the main lobe from the monitor light, identification circuitry that identifies a cavity frequency of the optical cavity on the basis of the signal component, and calculation circuitry that calculates a difference between propagation distances between the reference light and the measurement light on the basis of the cavity frequency and the beat signal.

Measurement apparatus and measurement method

A measurement apparatus includes a laser apparatus, a branch that branches a frequency-modulated laser beam into a reference light and a measurement light, a beat signal generator that generates a beat signal by mixing the reference light and a reflected light that is the measurement light radiated onto an object to be measured, a first analyzer that analyses a first signal component corresponding to a difference in a propagation distance between the reference light and the measurement light on the basis of the beat signal, a second analyzer that analyses a second signal component corresponding to a cavity frequency of an optical cavity on the basis of the beat signal, and calculation circuitry that calculates the difference in the propagation distance between the reference light and the measurement light.

A measurement apparatus includes a laser apparatus, a branching part that branches a frequency-modulated laser beam output by the laser apparatus into a reference light and a measurement light; a beat signal generation part that generates a beat signal by mixing a reflected light and the reference light, a conversion part that converts the beat signal into a digital signal at a first sampling rate and frequency-analyses it, an extraction part that extracts a signal component corresponding to a cavity frequency from the frequency-modulated laser beam, a digital filter that digitally filters the extracted signal component at a second sampling rate; and a calculation part that calculates a difference in a propagation distance between the reference light and the measurement light.

A measurement apparatus, including: a laser apparatus that outputs a frequency-modulated laser beam with a plurality of modes; a branching part that branches the frequency-modulated laser beam into a reference light and a measurement light; a beat signal generation part that generates a plurality of beat signals by mixing the reference light and a reflected light that is reflected by radiating the measurement light onto an object to be measured; a conversion part that converts the plurality of beat signals into digital signals by sampling the beat signals at a frequency greater than or equal to four times a resonator frequency of the laser resonator; and a calculation part that calculates a distance from the measurement apparatus to the object to be measured on the basis of the digital signals is provided.

Measurement apparatus and measurement method using a laser and beat signals

A laser apparatus, a measurement apparatus, and a measurement method are provided in which the laser apparatus outputs a frequency-modulated laser beam with a plurality of modes and includes: an optical cavity that has a gain medium for amplifying a light to be input, and an optical SSB modulator for shifting a frequency of the light amplified by the gain medium: and a control part that controls the optical SSB modulator to shift a frequency of a light to be input to the optical SSB modulator.

Growing community of inventors

Tsukuba, Japan

Hiroki Ujihara