ABSTRACT
We propose a new scheme for generating radially polarized light by mimicking optical activity using linear birefringence. It involves a birefringent spirally varying retarder sandwiched between two orthogonally oriented quarter-wave plates. Using Poincaré sphere representation, we show that the polarization transformation of such a scheme is equivalent to that of a spirally varying optical activity and is capable of generating radially polarized light. We demonstrate the proof-of-concept using y-cut crystalline quartz.
ABSTRACT
We demonstrate the coherent locking of two orthogonal polarized lasers by using polarization selective loss. The two orthogonal polarizations are locked coherently to produce a resultant polarization state that sees minimal cavity loss. In contrast to the Michelson locking schemes, our scheme has the advantage of easy tunability, which helps to routinely achieve near-perfect (>99%) combining efficiency even when the power of the two arms is highly imbalanced and is varied from a power ratio of unity to >5. We also demonstrate an interesting phenomenon in which a miniscule injection of an antiphase field component from one arm into another can significantly inhibit the locking mechanism.
ABSTRACT
We demonstrate the possibility to perform distributed quantum computing using only single-photon sources (atom-cavity-like systems), linear optics, and photon detectors. The qubits are encoded in stable ground states of the sources. To implement a universal two-qubit gate, two photons should be generated simultaneously and pass through a linear optics network, where a measurement is performed on them. Gate operations can be repeated until a success is heralded without destroying the qubits at any stage of the operation. In contrast with other schemes, this does not require explicit qubit-qubit interactions, a priori entangled ancillas, nor the feeding of photons into photon sources.
