Optical apparatus

An optical apparatus for examining a sample, the optical apparatus comprising:

• an illumination unit configured to emit illumination light in an illumination wavelength range onto the sample;
• a detection unit configured to collect detection light in a detection wavelength range from the sample, the illumination wavelength range and the detection wavelength range partially overlapping in an intermediate wavelength range;
• and
• a light separating device configured to separate the illumination light and the detection light, the light separating device comprising a beam splitter,
• wherein the beam splitter is a polarization-dependent beam splitter, such that:
• in a first wavelength range including the illumination wavelength range and excluding the intermediate wavelength range, the beam splitter transmits both light in a first polarization state and light in a second polarization state;
• in a second wavelength range including only the intermediate wavelength range, the beam splitter transmits the light in the first polarization and reflect the light in the second polarization state;
• and
• in a third wavelength range including the detection wavelength range excluding the intermediate wavelength range, the beam splitter reflects both the light in the first polarization state and the light in the second polarization state.