초록 ▼

A high contrast ultrahigh speed optically-addressed ultraviolet light modulator exploits the optical anisotropy in a ZnO film epitaxially grown on (01 {overscore (1)}2) sapphire. This device, which could also be realized in a ZnO bulk crystal or similar wide bandgap material, achieves both high cont

A high contrast ultrahigh speed optically-addressed ultraviolet light modulator exploits the optical anisotropy in a ZnO film epitaxially grown on (01 {overscore (1)}2) sapphire. This device, which could also be realized in a ZnO bulk crystal or similar wide bandgap material, achieves both high contrast and high speed by exploiting the anisotropic bleaching of the anisotropic absorption and concomitant ultrafast polarization rotation near the lowest exciton resonances produced by femtosecond ultraviolet pulses. The resultant modulation in a preferred embodiment is characterized by a contrast ratio of 70:1, corresponding to a dynamic polarization rotation of 12.degree., and decays to a quasi-equilibrium value within 100 ps.

대표청구항 ▼

1. A high contrast, high speed ultraviolet light modulator comprising:a light source; a semiconductor having a bandgap in the ultraviolet range grown on a substrate surface of low rotation symmetry whereby the semiconductor exhibits optical anisotropy; a pulse generator for delivering a pulsed modul

1. A high contrast, high speed ultraviolet light modulator comprising:a light source; a semiconductor having a bandgap in the ultraviolet range grown on a substrate surface of low rotation symmetry whereby the semiconductor exhibits optical anisotropy; a pulse generator for delivering a pulsed modulating beam for the optical control of the optical anisotropy whereby the light source is modulated.