Etching Profile Control of Alignment Spring for Combining MEMS Micro-Channel Device and Optical Fibers

Abstract

The micro-channel devices (e.g., sensing the optical spectrum of the liquid in the micro-channel) can be well combined with optical fiber. Recent progress in the super continuum light is attractive. Two (input and output) fibers are set inside a MEMS device. The gap between them becomes the sample space for the measurement. For combining the micro-channel device and optical fibers, the mechanical alignment becomes important [1]. Figure 1 shows the schematic drawing of the bias springs pushing the fiber to the reference plane. The reversely tapered profile (B-B’) is for setting the fiber not only the left side (in-plan direction) but also vertically. The conventional vertical spring (A-A’) only works in-plane direction. The fabrication bases on two different plasma etching conditions and the delayed mask technique. Figure 2 shows the device with the optical fiber inserted manually. Alignment is obtained by the spring. The angle of the reverse taper is about 1 degree pushing the fiber downside. Figure 3 shows the optical signals. Black curve is obtained when the light source is directly connected with the spectrum analyzer. Red and blue curves are obtained from the device with the bias springs with the reversely tapered and the vertical profile. The optical transmission rate improves by about 2-times.