Quantum bit string sealing

Though it was proven that secure quantum sealing of a single classical bit is impossible in principle, here we propose an unconditionally secure quantum sealing protocol which seals a classical bit string. Any reader can obtain each bit of the sealed string with an arbitrarily small error rate, while reading the string is detectable. The protocol is simple and easy to be implemented. The possibility of using this protocol to seal a single bit in practical is also discussed.Comment: Add a discussion on the possibility of sealing a single bit in practica

Optical power limiting and stabilization using a two-photon absorbing neat liquid crystal in isotropic phase

[[abstract]]This letter reports on a neat liquid crystal that incorporates a two-photon-absorbing chromophore in its structure. The nonlinear optical properties including two-photon-induced fluorescence spectrum and decay behavior, as well as the effective two-photon absorption coefficient of this liquid crystal in its isotropic phase are presented. Fairly good optical limiting and stabilization performance with this nonlinear material have been achieved by using ;815-nm and ;5-ns laser pulses[[notice]]補正完畢[[journaltype]]國內[[booktype]]紙

The relationship between two flavors of oblivious transfer at the quantum level

Though all-or-nothing oblivious transfer and one-out-of-two oblivious transfer are equivalent in classical cryptography, we here show that due to the nature of quantum cryptography, a protocol built upon secure quantum all-or-nothing oblivious transfer cannot satisfy the rigorous definition of quantum one-out-of-two oblivious transfer.Comment: 4 pages, no figur

Erratum: Quasi-collinear and partially degenerate four-wave mixing: An alternative explanation of the phase-conjugation property of backward stimulated scattering [JETP 88, 235–245 (February 1999)]

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45799/1/11447_2005_Article_698.pd

Quasi-collinear and partially degenerate four-wave mixing: An alternative explanation of the phase-conjugation property of backward stimulated scattering

A quasi-collinear and partially degenerate four-wave mixing model is proposed to explain the optical phase-conjugation property of various types of stimulated backscattering. According to this model, after passing through a phase-disturbed medium or an aberration plate, the input pump beam can be resolved into two portions: a stronger undisturbed regular portion and a weaker phase-disturbed irregular portion. These two portions interfere with each other and create a volume holographic grating in the pumped region of the scattering medium. Only the stronger undisturbed portion of the pump field can excite an initial backward stimulated scattering beam with a regular wavefront. When the latter (as a reading beam) passes through the induced holographic grating, a diffracted wave will be created and then amplified together with the reading beam. A rigorous mathematical analysis shows that under certain conditions the combination of these two portions (the reading wave and the diffracted wave) of the backward stimulated scattering can be an approximate phase-conjugate field of the input pump field. The major theoretical conclusions are basically supported by the experimental results based on a specially designed two-beam interference setup.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45798/1/11447_2005_Article_570.pd