A system for a high resolution optical spectrum analyzer (OSA) using various optical configurations to reduce polarization dependent loss (PDL) is disclosed. The system may include a birefringent element to receive an input optical beam. The birefringent element may then split the optical beam into at least two exit beams. The system may also include an optical configuration comprising at least one optical element. The optical configuration may receive the at least two exit beams from the birefringent element and transform at least one of the two exit beams using the at least one optical element to provide two parallel beams with parallel polarizations. The optical configuration may then output the two parallel beams with parallel polarizations to a downstream optical element, such as a diffraction grating, or other optical element.