Demonstration of 405-nm Two-Tone Lightwave for Terahertz-wave Generation at InGaN Photodiode

Terahertz-wave has been attracting attention for high-speed wireless communication and photomixing is considered to be a promising method for generating terahertz-waves. Since the output power of the conventional InGaAsP-based photomixer saturates due to its lower voltage resistance, an InGaN-based photomixer with higher voltage resistance is under investigating. One of the essential technologies of InGaN-based photomixing is two-tone single-mode lightwave. In this paper, we devised a method to make a two-tone lightwave using a 405-nm laser and a periodic optical filter. We successfully demonstrated the two-tone lightwaves for four different terahertz bands.