Abstract
Optically bistable arrays are being developed to produce devices which will
process and store information. It is of interest to optimise array dimensions for
reasons of cost and speed. The minimum array dimension is restricted due to the cross-talk between the array elements (pixels). The cross-talk will induce unwanted switching between bistable states if packing is too dense. In InSb and GaAs the cross-talk is predominantly diffusive and it is this type of cross-talk which is examined in this paper. Minimum pixel separation has been predicted for dispersively bistable arrays [1-3] to the order of the material diffusion length. The aim here is to examine absorptive arrays. We are not concerned with absorptive optical bistability [4], in which a saturable absorber in a cavity is bleached above a certain input intensity, with hysteresis. Instead we deal with cavity-less `optical bistability due to increasing absorption', in which the coupling of material parameter (e.g. temperature or carrier density) to the optical field increases as carrier excitation increases. This has been demonstrated [5] in amorphous semiconductor films and more recently [6] in multiple quantum well devices . Similar analytical methods are used as with the dispersive array, and these are compared with numerical predictions of dynamics to give a minimum pixel spacing.
process and store information. It is of interest to optimise array dimensions for
reasons of cost and speed. The minimum array dimension is restricted due to the cross-talk between the array elements (pixels). The cross-talk will induce unwanted switching between bistable states if packing is too dense. In InSb and GaAs the cross-talk is predominantly diffusive and it is this type of cross-talk which is examined in this paper. Minimum pixel separation has been predicted for dispersively bistable arrays [1-3] to the order of the material diffusion length. The aim here is to examine absorptive arrays. We are not concerned with absorptive optical bistability [4], in which a saturable absorber in a cavity is bleached above a certain input intensity, with hysteresis. Instead we deal with cavity-less `optical bistability due to increasing absorption', in which the coupling of material parameter (e.g. temperature or carrier density) to the optical field increases as carrier excitation increases. This has been demonstrated [5] in amorphous semiconductor films and more recently [6] in multiple quantum well devices . Similar analytical methods are used as with the dispersive array, and these are compared with numerical predictions of dynamics to give a minimum pixel spacing.
Original language | English |
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Pages (from-to) | 627-638 |
Number of pages | 12 |
Journal | Journal of Modern Optics |
Volume | 37 |
Issue number | 4 |
DOIs | |
Publication status | Published - 1990 |