Figure 5
From: Free-standing millimeter-range 3D waveguides for on-chip optical interconnects
Interconnected microLEDs via a 3D polymer waveguide. (a) Back scattered light intensity images of a micro-ring LED with a diameter of 14 µm. Top and bottom images are zoomed out and zoomed in views, respectively. (b) Camera image of two 250 µm long waveguides, interconnecting two pairs of microLEDs facing each other. (d) SCMOS camera image of a 3D polymer waveguide, interconnecting a pair of microLEDs with a circular pillar 14 μm diameter, where the input microLED is biased at 0 V. (d) Input microLED biased at a voltage of 1.4 V via a ground-signal-ground electrical probe. The emitting light is coupled to the 3D waveguide, reaching the output at the second microLED. (e) 2D FDTD simulation of light propagating in an accurate model of a 3D waveguide microprinted on a GaAs semiconductor chip containing microLEDs. The simulation consider Gaussian sources varying in angle from − 30° to 60° in relation to the substrate normal vector, and 10 wavelength points centered around 860 nm with a span of 35 nm, similar to the microLED emission. Simulation details can be consulted in supplemental document section S6 and a 2D FDTD simulation of a 3D waveguide without taper defects in Figure S5.
