Optical level control device, method for controlling same, and laser application device

An optical level control device comprising:

• a wavelength-dependent wavelength plate that receives a light beam containing a first wavelength which is linearly polarized and a second wavelength which is linearly polarized, said wavelength plate functioning as a half-wave plate with respect to said first wavelength and as a full-wave plate with respect to said second wavelength, and
• a polarization beam splitter which receives said first wavelength and said second wavelength from said wavelength plate and transmits and reflects said first wavelength and said second wavelength, such that a transmittance of said first wavelength and a transmittance of said second wavelength are based on the polarization of said first wavelength and said second wavelength,
• wherein said wavelength plate and said polarization beam splitter can be rotated;
• and
• wherein a rotation angle of said wavelength plate and said polarization beam splitter is adjusted to set the transmittance of said first wavelength and the transmittance of said second wavelength transmitted through said polarization beam splitter.

A method for controlling an optical level control device comprising:

• at a wavelength dependent wavelength plate, receiving a light beam comprising a first wavelength which is linearly polarized and a second wavelength which is linearly polarized and rotating a polarization of said first wavelength and rotating a polarization of said second wavelength;
• at a polarization beam splitter, receiving said first wavelength and said second wavelength output from said wavelength-dependent wavelength plate, and transmitting and reflecting said first wavelength and said second wavelength through said polarization beam splitter such that a transmittance of said first wavelength and a transmittance of said second wavelength are based on the polarization of said first wavelength and said second wavelength;
• rotating said wavelength plate and said polarization beam splitter;
• and
• adjusting rotation angles of said wavelength plate and said polarization beam splitter to set the ratio of the first wavelength to the second wavelengths transmitted through said polarization beam splitter.

A method for controlling an optical level control device comprising:

• at a wavelength dependent wavelength plate, receiving a light beam comprising a first wavelength which is linearly polarized and a second wavelength which is linearly polarized and rotating a polarization of said first wavelength and rotating a polarization of said second wavelength;
• at a polarization beam splitter, receiving said first wavelength and said second wavelength output from said wavelength-dependent wavelength plate, and transmitting and reflecting said first wavelength and said second wavelength through said polarization beam splitter such that a transmittance of said first wavelength and a transmittance of said second wavelength are based on the polarization of said first wavelength and said second wavelength;
• and
• independently rotating said wavelength plate and said polarization beam splitter.