Forty years ago, Star Wars gave the public a futuristic preview of augmented reality (AR): in a 3D hologram, Princess Leia appeared standing on a physical table. The young audience of yesterday is wearing AR headsets today. However, images are often “primitive, blurred, low in resolution, slow to refresh, [and] subject to a narrow field of view.” This paper discusses three approaches to meeting the optical challenges of AR.

The first approach uses “a semi-reflective, semi-transparent curved mirror” and is connected to a projection system. Distortion and ghosting require optical or electronic correction that could result in lower resolution.

The second approach uses “diffractive, reflective, holographic, or polarizing optics to guide ... a side-mounted source to create an image.” It is smaller, lightweight, and of good quality, though very expensive. The view is more limited than with a curved mirror. Examples include Microsoft’s Magic Leap and Akonia Holographics, acquired by Apple last year.

In the third approach, users wear a headset with a built-in camera. The current time it takes for an image to be presented to the eye is slow. Lower latency can be done with more powerful cameras for a faster image refresh. Jesse Schell, CEO of Schell Games and a professor at Carnegie Mellon, predicts that this approach “will capture 80 percent of the market for industrial and military applications within five years.”

The author keeps the article entertaining by mentioning research efforts by Intel and other vendors. However, pictorial examples of each approach would have been helpful, and the article lacks information on the IEEE standards relevant to AR. Those interested in the optical challenges of AR headsets should read it.