EXTERNAL CAVITY DIODE LASER ARRANGEMENT

A laser arrangement including a laser element; a volume Bragg grating, VBG, for providing optical feedback to the laser element along a beam path; a polarizing beam splitter, PBS, arranged in the beam path between the laser element and the VBG; and a polarization-modifying element arranged in the beam path between the PBS and the VBG element; wherein the polarization-modifying element is structured and arranged to alter a polarization state of light reflected from the VBG such that the PBS is operative to divide said light reflected from the VBG into a first portion that provides the optical feedback to the laser element and a second portion that provides an output beam from the laser arrangement. Embodiments may be useful for low wavenumber Raman spectroscopy.