Patent ID: 8164831

Claim:
A device, comprising: a polarization beam splitter (PBS) to receive an input optical beam with a coherent length and to split the input optical beam into a first beam and a second beam polarized orthogonal to said first beam; a first reflector positioned relative to said PBS to reflect said first beam back to said PBS; a first polarization element located between said first reflector and said PBS to rotate a polarization of a reflection of said first beam at said PBS to be perpendicular to said first beam when initially exiting said PBS; a second reflector positioned relative to said PBS to reflect said second beam back to said PBS; and a second polarization element located between said second reflector and said PBS to rotate a polarization of a reflection of said second beam at said PBS to be perpendicular to said second beam when initially exiting said PBS, wherein said first and said second reflectors are positioned to produce a difference in optical paths of said first and said second beams upon being reflected back to said PBS that is greater than said coherent length and that light of said first beam and light of said second beam upon being reflected back to said PBS are not coherent to each other and combined light produced by said PBS from the light of said first beam and the light of said second beam upon being reflected back to said PBS is depolarized.