Low power spatial light modulator with pharaonis phoborhodopsin

All-Optical Switching in Pharaonis Phoborhodopsin Protein Molecules

“…This apparent phase shift of TSI saturates after a certain value, maintaining the switched signal profile and exhibits a continuous decrease in contrast. [20]- [24] As the modulating pulse appears, the TSI switches off after a certain time lag. This time lag appears due to the time taken by the molecules to relax from the long lifetime pR intermediate that does not absorb the signal beam at 560 nm, to the probed pR state.…”

“…Theoretical simulations have been carried out by numerically solving the nonlinear time-dependent equations (1)- (5), using the experimentally measured lifetimes of the pR , pR , and pR states and the typical values of other parameters reported in literature as given in Table I [20]- [24]. Fig.…”

“…To simulate the effect of the intensities of both the modulating and signal beams, we consider the ppR molecules exposed to light beams of intensities and , which modulate the population densities of different intermediate states through the excitation and de-excitation processes. These can be described by the rate equations in the following form [14], [22]- [24]: for to (1) where , to 7 represents the population densities of ppR, pR , pR , pR , pR , pR , and pR states, respectively; and are the absorption cross sections and rate constants of respective states; subscript denotes the value at signal wavelength; and is the quantum efficiency for the pR pR transition [19]. and are the photon density fluxes of the modulating laser and signal beams, respectively, i.e., ratio of the intensity to the photon energy at respective wavelengths.…”

“…Recently, we have reported theoretical designs of low-power all-optical spatial light modulators and logic gates with WT-ppR and its mutants [22]- [24].…”

Fast photonic switching in pharaonis phoborhodopsin protein molecules

“…The naturally longer lifetimes of its later intermediates in its native state lead to all-optical switching at low powers. Very recently, we have reported the designs of low-power all-optical spatial light modulators, switches and logic gates with (wildtype) WT-ppR and its mutants [18][19][20]. In addition to high thermal stability of the K state of ppR (transition temperature 183 K) in comparison to the K state of bR, the fast relaxation rate of the K state of ppR ($50 ns) at room temperature [16] motivated us to analyze all-optical switching in ppR for fast digital operation by utilizing its K-state population changes.…”