OPTICAL APPARATUS

An optical apparatus (100) for examining a sample (102), comprises an illumination unit (104) configured to emit illumination light (106) in an illumination wavelength range (W3) onto the sample (102), and a detection unit (108) configured to collect detection light (122) in a detection wavelength range (W1+W2) from the sample (102). The illumination wavelength range (W3) and the detection wavelength range (W1+W2) partially overlap in an intermediate wavelength range (W2). A light separating device (114) is configured to separate the illumination light (106) and the detection light (122), wherein the light separating device (114) comprises a beam splitter (116). The beam splitter (116) has a first splitting characteristic with one of transmitting and reflecting light of at least a first polarization state (P-pol, S-pol) in the illumination wavelength range (W3) excluding the intermediate wavelength range (W2). The beam splitter (116) has a polarization-dependent second splitting characteristic with said one of transmitting and reflecting light of the first polarization state (P-pol, S-pol) and the other of transmitting and reflecting light of a second polarization state (S-pol, P-pol) in the intermediate wavelength range (W2). The beam splitter (116) has a third splitting characteristic with the other of transmitting and reflecting light of both the first polarization state (P-pol, S-pol) and the second polarization state (S-pol, P-pol) in the detection wavelength range (W1+W2) excluding the intermediate wavelength range (W2).