  The omnipresent tilt-to-length coupling in two-beam laser interferometers,
frequently a nuisance in precision measurements, vanishes for the singular case
of two beams with identical parameters and complete detection of both beams
without clipping. This effect has been observed numerically and is explained in
this manuscript by the cancellation of two very different effects of equal
magnitude and opposite sign.
  This paper was published in Applied Optics and is made available as an
electronic reprint with the permission of OSA. The paper can be found at the
following URL on the OSA website:
[http://www.opticsinfobase.org/ao/abstract.cfm?URI=ao-54-5-1010]. Systematic or
multiple reproduction or distribution to multiple locations via electronic or
other means is prohibited and is subject to penalties under law.
