Patent ID: 6754431
Filing Date: 2004-06-22
Classification: G02B

Abstract:
A variable optical attenuator comprising:a first port; a second port; a mirror located to direct light output by said first port to said second port; a controller coupled to said mirror to align said mirror such that a predetermined fraction of light output by said first port is coupled into said second port, wherein said predetermined fraction is less than a maximum fraction corresponding to optimal coupling of said light into said second port; a laser coupled to output a control light beam; a first beam splitter coupled to reflect the control light beam to the mirror; a second beam splitter coupled to receive the control light beam from the mirror and to reflect the control light beam to a position sensing detector; and a position sensing detector coupled to receive the control light beam and to couple a signal indicating a position at which the control light beam is incident on the position sensing detector to the controller.