Fig. 2: Optical characterization of the Neuropixels Opto probe.
From: Neuropixels Opto: combining high-resolution electrophysiology and optogenetics
a, Efficiency of the emitters, showing output light power as a percentage of input power for 14 red (top) and blue (bottom) emitters from n = 31 probes. Each dot corresponds to one emitter from one probe. Curves show the average over probes. b, Top view, showing light propagation from a red and blue emitter, measured in water. The color (color scale in d) indicates the maximum projection. These measurements were made on a test structure where emitters were placed 25 μm apart rather than the 100 μm of the prototype probe and this led to small imaging artifacts visible in the red emission (top), where two emitters to the side of the central one also appear to emit light. c, Same data, projected over a side view. d, Same data, projected over a front view. Dashed lines delineate the width of the probe. e, Section on a plane located 52 μm away from the shank, showing areas where power density is >10 mW mm−2 (for a 100-μW output) for three nearby emitters.
