Memory photon-mode optical

Achieved NotoI °pi>cal memory, photon-mode spatial light modulation, ulttafast optical parallel switching, optical enhancement of nonlinear optical properties, etc... 

Y. Yokoyama, T. Yamani, and Y. Kurita, Photochromism of a protonated 5-dimethylaminoindolyl-ful-gide A model of a destructive readout for a photon mode optical memory. J. Chem. Soc., Chem. Commun. 1991, 1722-1724. 

F. Matsui, H. Taniguchi, Y. Yokoyama, K. Sugiyama, and Y. Kurita, Application of photochromic 5-dimethylaminoindolyl fulgide to photon-mode erasable optical memory media with non-destructive ability based on wavelength dependence of bleaching quantum yield, Chem. Lett., 1994, 1869-1872. 

A photochromic compound is characterized by its ability to alternate between two different chemical forms having different absorption spectra in response to light of appropriate wavelengths. Photochromic materials are promising as recording media for optical memory, because the media store erasable/ rewritable data in photon mode. Because the data-recording mechanism is based on the photochemical reaction of each molecule, extremely high spatial resolution is expected. 

Photons in quantum optical cavities also constitute excellent qubit candidates [52]. Resonant coupling of atoms with a single mode of the radiation field was experimentally achieved 25 years ago [53], and eventually the coherent coupling of quantum optical cavities with atoms or (simple) molecules was suggested as a means to achieve stable quantum memories in a hybrid quantum processor [54]. There might be a role to play for molecular spin qubits in this kind of hybrid quantum devices that combine solid-state with flying qubits. 

The dual-function utility (photon emission in forward bias and photon detection in reverse bias) can be employed to fabricate smart display matrices [148]. By presetting the device in the photodetecting mode (zero or reverse bias), each pixel can sense an optical signal and transfer that signal to the memory in the driving circuit, similar to the process in a photodiode... 

It is important to point out that even at 77 = 0 the observed value V = 0.942 0.006 is far from its ideal value of V = 0. One important source of error is the finite retrieval efficiency, which is limited by two factors. Due to the atomic memory decoherence rate 7C, the finite retrieval time Tr always results in a finite loss probability p 7c Tr. For the correlation measurements we use a relatively weak retrieve laser ( 2 mW) to reduce the number of background photons and to avoid APD dead-time effects. The resulting anti-Stokes pulse width is on the order of the measured decoherence time, so the atomic excitation decays before it is fully retrieved. Moreover, even as 7C —> 0 the retrieval efficiency is limited by the finite optical depth q of the ensemble, which yields an error scaling as p 1/ y/rj. The measured maximum retrieval efficiency at 77 = 0 corresponds to about 0.3. In addition to finite retrieval efficiency, many other factors reduce correlations, including losses in the detection system, background photons, APD afterpulsing effects, and imperfect spatial mode-matching. 

---