All-Optical Switching in Pharaonis Phoborhodopsin Protein Molecules

Fast photonic switching in pharaonis phoborhodopsin protein molecules

“…In this paper, we theoretically realize fast all-optical switching operation with nanosecond speed, in ppR, which is much higher in comparison to earlier reported switching speeds in seconds [20].…”

“…ppR exhibits large absorption changes in the entire visible region and, hence, can provide an excellent opportunity of controlling switching characteristics, alloptically [20]. In this paper, we theoretically realize fast all-optical switching operation with nanosecond speed, in ppR, which is much higher in comparison to earlier reported switching speeds in seconds [20].…”

“…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.…”

“…The ppR molecules are considered to be exposed to a temporally varying pump laser intensity I 0 m (t), which modulates the population densities (N) of different states through excitation and de-excitation processes. The number of intermediates in the photocycle and their spectral and kinetic characteristics depend on the physical, chemical and genetic properties of the sample [15][16][17][18][19][20]. For example, in our previous experimental study of all-optical switching in ppR, in addition to six states of the typical photocycle, the sample contains an additional longer lived ppR 0 state [20].…”

“…The number of intermediates in the photocycle and their spectral and kinetic characteristics depend on the physical, chemical and genetic properties of the sample [15][16][17][18][19][20]. For example, in our previous experimental study of all-optical switching in ppR, in addition to six states of the typical photocycle, the sample contains an additional longer lived ppR 0 state [20]. To realize fast photonic switching by exploiting K-state dynamics, this additional longer lived ppR 0 state may be ignored as it does not play any role at lower time scale.…”