Augmented reality spectroscopy

A wearable spectroscopy system comprising:

• a frame removably coupleable to a user's head;
• a head-mountable display attached to the frame, the head-mountable display comprising a waveguide stack configured to output light with selectively variable levels of wavefront divergence to an eye of the user;
• at least one outward-facing light source coupled to the frame and configured to emit light with at least two different wavelengths;
• at least one electromagnetic radiation detector coupled to the frame and configured to receive reflected light from a target object irradiated by the emitted light;
• an absorption database of light absorption properties of at least one material;
• a controller operatively coupled to the at least one outward-facing light source and the at least one electromagnetic radiation detector, the controller configured to cause:
• emission of pulses of light by the at least one outward-facing light source;
• detection, by the at least one electromagnetic radiation detector, of levels of light absorption related to the emitted pulses of light and reflected light from the target object;
• and
• matching of detected levels of light absorption with light absorption properties stored in the absorption database;
• and
• a graphics processor unit configured to display an output to the user.