Apparatus comprising an all-optical gate
AssigneeAT&T Bell Laboratories
InventorsMohammed N. Islam, Richard E. Slusher
Life of this patent
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Abstract
It has been recognized that AlGaAs-containing planar waveguides can be advantageously used in all-optical gates for wavelengths in the range 1.2-1.7 .mu.m. In particular, such waveguides can produce in radiation pulses of center wavelength, .lambda..sub.s a phase shift of magnitude .pi. or larger while, at the same time, causing attenuation of the pulse by less than 1/e, provided hc/.lambda..sub.x <E.sub.g /2, where E.sub.g is the bandgap associated with the Al.sub.x Ga.sub.2-31 x As-contianing waveguide. In preferred embodiments .lambda..sub.s and/or x are selected such that [hc/(.lambda..sub.s -.DELTA..lambda.]<E.sub.g /2, where .DELTA..lambda. is chosen such that 99% of the pulse energy is contained in the spectral region .lambda..sub.s .+-..DELTA..lambda..
Claims7
An article comprising an all-optical gate comprising optical waveguide means of effective length L, the waveguide means adapted for guiding electromagnetic signal radiation of wavelength .lambda..sub.s, associated with said waveguide means being a bandgap energy E.sub.g, a non-linear refractive index n.sub.2 and an absorption coefficient .alpha., with n.sub.2 and .alpha. being such that, in the presence of a control pulse of electromagnetic radiation, a pulse of signal radiation of centerwavelength .lambda..sub.s can, while propagating through said waveguide means, undergo a phase shift of magnitude at least equal to .pi. while, at the same time, undergo attenuation by less than e.sup.-1 ;
- characterized in that
- a) 1.2 .mu.m<.lambda..sub.s <1.7 .mu.m;
- and
- b) the optical waveguide means are planar semiconductor waveguide means comprising Al.sub.1-x Ga.sub.x As, with 0<x<1, with x selected such that (hc/.lambda..sub.s)<E.sub.g /2, where h is Planck's constant, and c is the speed of light in vacuum.
Dependencies are inferred from the claim text.