Apparatus for inspecting surface of object

An apparatus for inspecting a surface of an object, the apparatus comprising:

• a light source for emitting pulsed laser light of a predetermined wavelength;
• a second-harmonic generation element configured to generate a first second-harmonic of the pulsed laser light;
• a phase modulation element configured to modulate a phase of the first second-harmonic at a predetermined frequency;
• a lighting optical system configured to irradiate the pulsed laser light and the first second-harmonic onto the surface of the object, the object receiving the pulsed laser light irradiated thereto to generate a second second-harmonic;
• and
• a light-receiving optical system including a detector and a short pass filter, and configured to allow the first second-harmonic and the second second-harmonic to be incident on the detector while the first second-harmonic and the second second-harmonic are coaxial with each other,
• wherein the detector is configured to receive the first second-harmonic and the second second-harmonic and convert the first second-harmonic and the second second-harmonic into an electrical signal, and
• wherein the short pass filter is configured to remove the pulsed laser light of the predetermined wavelength.

An apparatus for inspecting a surface of an object, the apparatus comprising:

• a light source for emitting pulsed laser light of a predetermined wavelength through an isolator;
• an intensity modulator configured to change an intensity of the pulsed laser light;
• a second-harmonic generation element configured to generate a first second-harmonic of the pulsed laser light based on an output of the intensity modulator;
• a phase modulation element configured to modulate a phase of the first second-harmonic at a predetermined frequency;
• a lighting optical system configured to irradiate the pulsed laser light and the first second-harmonic onto the surface of the object, the object receiving the pulsed laser light irradiated thereto to generate a second second-harmonic;
• and
• a light-receiving optical system including a detector and a polarizer, and configured to allow the first second-harmonic and the second second-harmonic to be incident on the detector while the first second-harmonic and the second second-harmonic are coaxial with each other,
• wherein the detector is configured to receive the first second-harmonic and the second second-harmonic and convert the first second-harmonic and the second second-harmonic into an electrical signal, and
• the polarizer allows a polarized state of the first second-harmonic and a polarized state of the second second-harmonic to be identical with each other.