Dispersion compensation for full-color virtual-imaging systems with a holographic off-axis mirror

In recent years, tele-communication using video calling functions of, e.g., PCs and smartphones has been used in various situations, such as conversations in personal life and online meetings at work. Aiming at the enhancement of the sense of presence in video telecommunication systems, a holographic off-axis mirror, which is a see-through off-axis reflector fabricated as a holographic optical element (HOE), is utilized as an upright screen for a virtual- image display and a face image capture with eye-contact. Since the chromatic dispersion of the HOE causes image blur, we previously proposed a optical dispersion compensation technique for this system. In this paper, we extend the dispersion-compensation technique to full-color virtual-imaging systems with a holographic off-axis mirror exposed by red, green, and blue lasers. We demonstrate the proof of concept system experimentally using an A4-sized full-color holographic off-axis mirror. We also apply the same concept to the off-axis image capturing system using a full-color holographic mirror, which is also experimentally demonstrated. The proposed full-color virtual-image display and camera system will enable more attractive visual telecommunication systems, such as video phone or online conference.