110 likes | 206 Views
Imaging With Entangled Photons. Timothy Shokair Physics 138 May 10, 2005. What is Entanglement?. Term Coined by Schr ödinger in response to famous 1935 EPR Paradox paper.
E N D
Imaging With Entangled Photons Timothy Shokair Physics 138 May 10, 2005
What is Entanglement? • Term Coined by Schrödinger in response to famous 1935 EPR Paradox paper. • EPR claimed Quantum mechanics was incomplete, Schrödinger responded with a statement based on the Copenhagen Interpretation of QM. • Paradox was left alone for 30 years until Bell came up with his theory on hidden variables. • Experiment was done by Freedman and Clauser in 1972 that showed strong evidence against local hidden variable theories. • Further proof by Kwait, Eberhard, Steinberg and Chiao that was unambiguous.
How do we get entangled photons? • Spontaneous Parametric Down Conversion (SPDC). • Three Photon process: One UV photon into a crystal where it is absorbed and two lower energy photons emitted. • The two photons emerge in an entangled state. • See Keller and Rubin Phys. Rev. A v.52 pg. 1534 for full theory.
The Crystal • Beta Barium Borate (BBO) highly nonlinear. • Two types of cuts Type-I, producing photons polarized parallel to each other and Type-II where they are orthogonal. • The photons are termed Signal and Idler.
An Experiment • Pittman, Shih, Strekalov, and Sergienko performed and experiment where they exploited entangled photons to create an image. • University of Maryland Baltimore County December 1994 • Mathematical Details of the Geometry described in a later paper by the same group.
Holography Experiment • Proposed by Abouraddy, Saleh, Sergienko and Teich at Boston University in 2001. • Using similar methods to the UMBC group the propose to use entangled photons for 3D holography. • Signal Photon scatters on remote object while the Idler is locally manipulated using conventional optics.
Conclusion • Entangled Photons have been used to create images and give the possibility of high resolution. • Holography could be used in a completely non-classical way by imaging a remote object in an isolated chamber where light can enter but not escape.