Holographic observation method and device

A holographic observation method comprising:

• emitting a light beam generated by driving a semiconductor laser light source with an electric current with an alternating-current component superimposed from the semiconductor laser light source and casting the light beam emitted from the semiconductor laser light source to an observation object while returning a portion of the light beam to the semiconductor laser light source;
• forming a hologram by causing a light beam transmitted through or reflected by the observation object to interfere with a reference light beam;
• and
• obtaining information on the observation object by performing image processing on the hologram.

A holographic observation method comprising:

• casting a light beam having a predetermined spectral width and predetermined spectral intensity to have predetermined coherency to an observation object;
• forming a hologram by causing a light beam transmitted through or reflected by the observation object to interfere with a reference light beam;
• and
• obtaining information on the observation object by performing image processing on the hologram.

A holographic observation device comprising:

• a) a semiconductor laser light source;
• b) a current source that supplies a drive current with an alternating-current component superimposed to the semiconductor laser light source;
• c) an exposure optical system that causes a light beam emitted from the semiconductor laser light source driven with the drive current to be transmitted through or reflected by an observation object and interfere with light transmitted through or reflected at a different spot of the observation object;
• d) an image sensor that acquires an interference image of the light beam transmitted through or reflected by the observation object;
• and
• e) a return light forming unit that returns a portion of the light beam emitted from the semiconductor laser light source to the semiconductor laser light source.

A holographic observation device comprising:

• a) a semiconductor laser light source;
• b) a current source that supplies a drive current with an alternating-current component superimposed to the semiconductor laser light source;
• c) an exposure optical system that splits a light beam emitted from the semiconductor laser light source driven with the drive current into two light beams, and causes one of the two light beams to be transmitted through or reflected by an observation object;
• and
• d) an image sensor that acquires an interference image of the light beam transmitted through or reflected by the observation object and a light beam that is the other of the two light beams and is neither transmitted through nor reflected by the observation object.

A holographic observation device comprising:

• a) a light source that emits a light beam having a predetermined spectral width and predetermined spectral intensity to have predetermined coherency;
• b) an exposure optical system that causes the light beam to be transmitted through or reflected by an observation object and interfere with light transmitted through or reflected at a different spot of the observation object;
• and
• c) an image sensor that acquires an interference image of the light beam transmitted through or reflected by the observation object.

A holographic observation device comprising:

• a) a light source that emits a light beam having a predetermined spectral width and predetermined spectral intensity to have predetermined coherency;
• b) an exposure optical system that splits the light beam into two light beams, and causes one of the two light beams to be transmitted through or reflected by an observation object;
• and
• c) an image sensor that acquires an interference image of the light beam transmitted through or reflected by the observation object and a light beam that is the other of the two light beams and is neither transmitted through nor reflected by the observation object.

A light source unit comprising:

• a semiconductor laser light source;
• and
• a return light forming unit that returns a portion of a light beam emitted from the semiconductor laser light source to the semiconductor laser light source,
• wherein the return light forming unit includes a reflecting member that has a reflecting surface that reflects at least a portion of incident light and is arranged to be on an optical axis of the light beam emitted from the semiconductor laser light source and in an orientation that allows a normal line of the reflecting surface to be inconsistent with the optical axis.