This paper presents two types of attenuation-controllable 2×2 optical switches utilizing V-shaped 45-deg micromirrors. One type utilizes four single-face mirrors, and the other has a simplified configuration utilizing two double-face mirrors. The designed devices were fabricated on a silicon-on-insulator wafer with a structural layer of 80-µm thickness. Two pairs of lensed fibers with a focal length of 150 µm were aligned for optical characterization. Experiments on the simplified design showed optical insertion losses of less than 1.9 dB and on/off ratios larger than 70 dB. The optical power can be controlled up to a maximum attenuation level of 50 dB within ±0.1 dB tolerance in the other channels. Because the overall optical performance of the two types was verified to be almost the same, the simplified design will be more desirable for practical applications.
This paper presents a 9×9 OXC (Optical Cross Connect) utilizing two-dimensional micro-lens scanners, each of which consists of eight 'L' shaped (spider-leg) stage-suspension springs and rotational comb-drive actuators. Silicon was used as a lens material because of the mechanical stability and optical transparency to infrared wavelength of 1.55 μm. The micro lens scanner was fabricated by lens-profile-transferring to the structural layer of an SOI wafer by the RIE (reactive ion etching) from thermally reflowed photoresist. The XY stage moved more than 55 μm independently in the X and Y directions with applied voltage of 65 V. In optical measurement, the coupling loss was 13 dB, and channel uniformity of 9×9 OXC was less than 4.5 dB.
We propose a micromachined 2x2 optical switch with variable optical attenuation. The proposed optical switch features expandability and integration utilizing four 45° micromirrors driven by four electrostatic comb actuators. These four micromirrors can move independently to reflect and/or partially block the optical signal. In order to reduce the insertion loss caused by long optical path length, the optical module employed anti-reflection coated lensed fibers. Two pairs of optical fibers were aligned in each single trench at both sides for cost-effective packaging. The device was fabricated using SOI (Silicon-On-Insulator) process with one photo-mask, and its experimental IL (Insertion Loss) and attenuation range were less than 1.53 dB and over 60 dB, respectively. Also the PDL (Polarization Dependent Loss) was less than 0.25 dB in the range of 30 dB.