  A new type of polarization sensitive interferometer is proposed, which is
named as Delta interferometer due to the geometry of the simplest
interferometer looks like Greek letter, Delta. To the best of our knowledge, it
is the first time that this type of interferometer is proposed. The main
difference between Delta interferometer and other existed interferometer, such
as Michelson interferometer, Mach-Zehnder interferometer, Young\rq{}s
double-slit interferometer, is that the two interfering paths are asymmetrical
in Delta interferometer, which makes it polarization sensitive. The visibility
of the first-order interference pattern observed in Delta interferometer is
dependent on the polarization of the incidental light. Optical coherence theory
is employed to interpret the phenomenon and a single-mode continuous-wave laser
is employed to verify the theoretical predictions. The theoretical and
experimental results are consistent. Delta interferometer provides a perfect
tool to study the reflection of electric field in different polarizations and
may find applications in polarization sensitive scenarios.
