Fig. 1. Structure diagrams of N×N microfluidic optical switch array. (a) Overall structure; (b) waveguide layer of switch unit;(c) structures of actuation layer and waveguide layer

Fig. 2. Working principle diagrams of 2×2 optical switch units. (a) Air is extracted and light is fully reflected; (b) air is injected and light passes through microchannel

Fig. 3. Waveguide intersecting zone

Fig. 4. Topology structures of N×N optical switch array. (a) Partial blocking type; (b) complete non-blocking type

Fig. 5. Optical transmission paths of 6×6 optical switch array. (a) Reflection number is 1; (b) reflection number is 3; (c) reflection number is 5

Fig. 6. Effect of optical path crossing. (a) Light path 3′→3 has only one reflection; (b) light path 3′→3 has three reflections; (c) light path 4′→4 has only one reflection; (d) light path 4′→4 has three reflections

Fig. 7. Optimal paths for 4×4 partially blocked switch array. (a)-(d) Input port is 3'; (e)-(g) input port is 4'

Fig. 8. Power transmission efficiency of different waveguide angles (microchannel width is 2.5 μm)

Fig. 9. Power transmission efficiency and maximum crosstalk for different microchannel widths. (a) Power transmission efficiency;(b) maximum crosstalk of output ports

Fig. 10. Optical field distributions of optical switch array. (a) Microchannel width is 1.0 μm; (b) microchannel width is 5.0 μm;(c) microchannel width is 2.5 μm.