Monolithic integrated-optic position/displacement sensor using waveguide gratings and QW-DFB laser

Semiconductor Optical Sensors

“…At a measurement distance of 20 mm, the signal current amplitude was about 1 nA on a 10 nA offset, where the sinusoidal signal variation with translation had a period of l /2 ; 427 nm [177]. Incorporation of the collimation function on-chip, in the final grating coupler, implied that this monolithic sensor did not require any further external optics for operation.…”

Optical displacement measurement with GaAs/AlGaAs-based monolithically integrated Michelson interferometers

“…[7], [9] and 1 nm resolution, at a distance of several centimeters, has been reported [8] for a glass-based double interferometer. A 100 nm resolution for short distances has also been demonstrated for a monolithic interferometer [12], but without phase-shift between the measurement signals.…”

“…Recently, Suhara [12] published a monolithically IO position sensor. This III-V-semiconductor-based device was configured as a double Michelson interferometer and consisted of a DFB laser, planar waveguides, and grating couplers but without a phase shift between the two reference beams.…”

Monolithic integrated-optic sensors using waveguide gratings and QW-DFB laser

“…Previously, the authors have studied monolithic integrated devices that function fully with one chip and have reported a monolithic integrated-optic position/displacement sensor (MIOPS) [7] and the monolithic integrated-optic disk pickup (MIODPU) [8]. In addition, a monolithic integrated Michelson interference-type displacement sensor that can measure displacement and its direction was reported by Hofstetter and others [9] although an external lens system was required.…”