A digital holographic imaging apparatus, comprising:
- an illumination portion comprising:
- an illumination light emission surface for emitting, as illumination light, coherent light of a specific wavelength toward an object side;
- and a reference light emission surface located on the opposite side to the object side relative to the illumination light emission surface, the reference light emission surface emitting, as reference light, the coherent light in a direction opposite to the illumination light;
- and
- an image sensor located on a reference light emission surface side of the illumination portion, the image sensor imaging an interference pattern between object light and the reference light, the object light being part of the illumination light having been modulated by the object and passed through the illumination portion, and the image sensor having a pixel array including two-dimensionally arranged pixels,
- wherein:
- the illumination portion further includes:
- a light source portion that emits the coherent light;
- and
- a plane optical waveguide portion that propagates the coherent light from the light source portion, wherein the plane optical waveguide portion includes a first material having a first refractive index and a second material having a second refractive index, wherein the first refractive index and the second refractive index are different from a refractive index of air,
- the plane optical waveguide portion includes:
- a plane optical waveguide having a plane serving as the illumination light emission surface and a plane serving as the reference light emission surface,
- the plane optical waveguide includes:
- a grating part formed by an interface between the first material and the second material, wherein the interface is located between the illumination light emission surface and the reference light emission surface, the plane optical waveguide diffracting, while propagating, the coherent light by the grating part so as to emit the coherent light as the illumination light from the illumination light emission surface, and also emit the coherent light diffracted by the grating part as the reference light from the reference light emission surface,
- the illumination portion further includes:
- a phase adjuster that adjusts a phase of the coherent light from the light source portion;
- and
- a light-adjusting plane optical waveguide that is located between the image sensor and the object, in tandem in a direction to be layered on the plane optical waveguide, and propagates the coherent light adjusted in phase by the phase adjuster, and
- the light-adjusting plane optical waveguide has a plane serving as the illumination light emission surface and a plane serving as the reference light emission surface, and emits the coherent light, as the illumination light, from the illumination light emission surface and also emits the coherent light, as the reference light, from the reference light emission surface.