Increasing Absorption Bistability of CdS at Room Temperature

Abstract

Visible-wavelength increasing absorption bistability a t room temperature is shown due to lattice heating of CdS in a fully cw-regime. Cross talk of two beams and the switching behaviour of the bistable system are investigated. For the first time critical slowing down is demonstrated for this type of optical bistability. Quantitative theoretical investigations based on the heat flow equations yield an excellent agreement with the experimental data.Optische Bistabilitat infolge wachsender Absorption im sichtbaren Wellenliingenbereich bei Raumtemperatur durch eine Gittererwiirmung von CdS in einem vollig sbtionaren Regime wird gezeigt. Das Ubersprechen zwischen zwei Lichtstrahlen und das Schaltverhalten des bistabilen Systems werden untersucht. Erstmalig wird ,,critical slowing down" fur diesen Typ optischer Bistabilitiit demonstriert. Qnantitative theoretische Untersuchungen, die von der Wiirmeleitungsgleichung ansgehen, ergeben eine ausgezeiclmete Ubereinstimmung mit den experimentellen Ergebnissen.

Experimental measurement of the relative stability of two stationary states in optically bistable ZnSe interference filters

“…dXldt = F(X,A). (1) In an analogy to a mechanical system 8 we can define a potential <I> d such that W 03 ~r-=-~~~~==::=3~::::======~ where Xo is an arbitrary state of the system. The relative stability of this system can be determined by the relative values of <I> d (a more stable system has a lower <I> d ).…”

Pump and probe spectroscopy of A Cr+3-doped glass

“…where E is the absorbed energy which depends on the laser intensity, D is the heat diffusion constant, ~ is the absorption coefficient, To is the surrounding air temperature and z0 is the effective relaxation time. magnitude of z0 is given by [10]:…”

Transverse Spatial Resolution of Thermo–Optical Hysteresis in CdS

“…We note that the temperature runaway conditions are expressed by three parameters D = k / C , h, and H . For CdS a t room temperature we used the values of C , k, and h as in [5]. I n our calculation the values of R and N were chosen such that the solution varied only negligibly if these parameters were changed.…”

“…The experimental and theoretical investigations have been focused on switching processes of the whole beam, neglecting the transverse variation of temperature within the excited spot. Recently in [5] the switching behaviour of the integrated power was studied assuming that the temperature does not change strongly across the excited spot. To show the influence of the transverse effects on the switching processes we present in this report the experimental results on spatial profiles of beams transmitted through CdS thin platelets at room temperature.…”