Femtosecond optical switches by squarylium dye J-aggregates films

Abstract Formation of Langmuir and spincoated films containing squarylium dye (SQ) J-aggregates and their femtosecond optical response are described. Pump–probe measurements show that saturable absorption of SQJ-films reveal ultrafast decay with time constants of 100–300 fs. We have applied SQJ-film to new femtosecond time-to-space conversion. A pump (gate) pulse and a train of four probe (signal) pulses were illuminated on the same area of the film in the direction of oblique and normal to the film-plane respectively. Demultiplexing operation for T bps optical signals was demonstrated with femtosecond nonlinear optical response of the SQJ-film.