Picosecond and nanosecond third order nonlinear optical characterization of Cu and Ni phthalocyanines using Z-scan technique

Abstract

Herein we present our results from the picosecond and nanosecond nonlinear optical studies of two novel phthalocyanines {[(SO 3 Na) 4 CuPc] and [(SO 3 Na) 4 NiPc]} using the Z-scan technique. Open aperture Z-scan data revealed that the picosecond nonlinear absorption was dominated by three-photon absorption while in the nanosecond domain reverse saturable absorption prevailed. Closed aperture data with nanosecond pulses indicated strong thermal, negative nonlinearity while picosecond excitation demonstrated positive nonlinearity. The nonlinearity in CuPc was higher than in NiPc in both the time domains. The nonlinear coefficients extracted from the fits to experimental data were large compared to some of the recently reported works on similar molecules.

Phthalocyanines for photonic applications: a new perspective

“…Complete details of the experiments can be found in most of our earlier publications [11][12][13][14][15][16][17][18][19][20][21]. Briefly 6 ns pulses (10 Hz, 532 nm), ~2 ps pulses (1 kHz, 800 nm), and ~100 fs pulses (1 kHz, 800 nm), 632.8 nm cw He-Ne laser beam were used for the Z-scan and DFWM experiments.…”

“…The high stability and capability of phthalocyanines, especially, to accommodate different metal ions within their cavity result in diverse optical properties. Even though nonlinear optical properties of surplus of phthalocyanines and their derivatives [11][12][13][14][15][16][17][18][19][20][21][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56] have been investigated till date to assess their performance for NLO applications there remains further scope for investigation of novel structures with superior figures of merit. The best optical limiting performance till date has been achieved using a phthalocyanine in tandem with another nonlinear optical material justifies the potential of these molecules [56].…”