Realization of augmented reality (AR) solutions is key towards the much-needed integration of digital content into the real world. This seamless integration of digital content with the real world in AR devices is achieved by displaying the information using a suitable projector in the field-of-view (FOV) of the user. One of the most practical solutions to realize this is a laser beam scanner (LBS) projector combined with a diffractive optical waveguide. Features such as a small form factor, high brightness, large color gamut, and low power-consumption make LBS a popular choice as the light engine for the emerging consumer market for AR displays where the primary focus is on obtaining a stylish wearable rather than an unwieldly head mounted device. As should be the case for any AR/VR/MR display, LBS plus waveguide solution must be evaluated against the IEC 60825- 1:2014 standard for a typical use case. In this manuscript, we will first describe a typical AR solution, a TriLite Trixel® 3 LBS plus a waveguide combiner. We will discuss the operating principle of such a device. Based on that we shall highlight stepwise the key considerations in such a system for ensuring a Class 1 operation in a typical AR use case as per the IEC 60825-1:2014 requirements.
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