Light-receiving/emitting composite unit, method for manufacturing the same, and displacement detection device

A displacement detection device for detecting displacement of an inspection target having a diffraction grating in the direction of a lattice vector, on the basis of an interference signal, the device comprising:

• a light source for emitting light;
• a beam splitter for splitting the light emitted from the light source into two light beams and radiating the two light beams;
• a first lens provided between the light source and the beam splitter;
• reflection means for reflecting two first diffracted light beams obtained as the two light beams radiated from the beam splitter are diffracted by the diffraction grating;
• light splitting means for combining two second diffracted light beams obtained as the first diffracted light beams reflected by the reflection means are diffracted by the diffraction grating, to generate combined light, and then splitting the combined light into plural light beams;
• polarization means for transmitting only a predetermined polarized component of the split combined light;
• light-receiving means for photoelectrically converting coherent light transmitted through the polarization means and thus generating the interference signal;
• and a second lens provided between the polarization means and the light-receiving means.

Alight-receiving/emitting composite unit comprising:

• a light source for emitting light;
• a polarizing beam splitter for splitting the light emitted from the light source into two light beams having different polarized components, then radiating the two light beams to an external optical system, and combining the two light beams reflected from the external optical system to generate combined light;
• light splitting means for splitting the combined light generated by the polarizing beam splitter into plural light beams;
• polarization means for transmitting only a predetermined polarized component of the split combined light;
• a lens unit for leading plural coherent light beams transmitted through the polarization means to predetermined positions, respectively;
• and light-receiving means for photoelectrically converting the plural coherent light beams led by the lens unit and thus generating an interference signal.

A displacement detection device for detecting displacement of an inspection target having a reflection-type diffraction grating in the direction of a lattice vector, on the basis of an interference signal, the device comprising:

• a light source for emitting light;
• a polarizing beam splitter for splitting the light emitted from the light source into two light beams having difference polarized components and radiating the two light beams;
• a phase plate arranged between the light source and the polarizing beam splitter and adapted for changing the polarization state of the light emitted from the light source and leading the light to the polarizing beam splitter;
• image formation means for causing image formation of the two light beams radiated from the beam splitter onto a lattice plate of the diffraction grating;
• reflection means for reflecting two first diffracted light beams obtained as the two light beams radiated from the beam splitter are diffracted by the diffraction grating;
• light splitting means for combining two second diffracted light beams obtained as the first diffracted light beams reflected by the reflection means are diffracted by the diffraction grating, to generate combined light, and then splitting the combined light into plural light beams;
• polarization means for transmitting only a predetermined polarized component of the split combined light;
• and light-receiving means for photoelectrically converting coherent light transmitted through the polarization means and thus generating the interference signal.

A displacement detection device for detecting displacement of an inspection target having a diffraction grating in the direction of a lattice vector, on the basis of an interference signal, the device comprising:

• a light source for emitting light;
• a polarizing beam splitter for splitting the light emitted from the light source into two light beams having difference polarized components and radiating the two light beams;
• reflection means for reflecting two first diffracted light beams obtained as the two light beams radiated from the beam splitter are diffracted by the diffraction grating;
• light splitting means for combining two second diffracted light beams obtained as the first diffracted light beams reflected by the reflection means are diffracted by the diffraction grating, to generate combined light, and then splitting the combined light into plural light beams;
• polarization means for transmitting only a predetermined polarized component of the split combined light;
• a lens unit for leading plural coherent light beams transmitted through the polarization means to predetermined positions, respectively;
• and light-receiving means for photoelectrically converting the plural coherent light beams led by the lens unit and thus generating the interference signal.