Optical switching in cadmium telluride using a light-induced electrode nonlinearity

Area of Science:

• Optoelectronics
• Semiconductor Physics
• Materials Science

Background:

• Electric field modulation is crucial for optical devices.
• CdTe:In offers unique photo-optic properties for electric field manipulation.

Purpose of the Study:

• To investigate the optical control of electric fields in CdTe:In.
• To explore the application of this effect in infrared spatial modulators.

Main Methods:

• Experimental and theoretical review of optically induced electric fields.
• Utilizing below-band-gap and near-band-gap light for field manipulation.
• Characterization of switching times, resolution, and energy efficiency.

Main Results:

• High electric fields (~20 kV/cm) are built up under the negative electrode using 850-920 nm light.
• Fields are erased with 800-840 nm light, following illumination patterns.
• Demonstrated 1D and 2D infrared spatial modulators with submicrosecond response and high resolution (170 line pairs/cm).
• Observed sizable Franz-Keldysh effects due to optically controlled fields.

Conclusions:

• Optically controlled electric fields in CdTe:In are a viable mechanism for advanced spatial light modulators.
• The technology enables high-performance infrared modulation with potential for various applications.
• Fast switching speeds and low energy consumption highlight the practical utility.