A low-power 2×2 multimode interference-Mach Zehnder interferometer thermo-optic switch is proposed and fabricated using a cross-linkable negative photoresist as core material. The waveguide can be easily fabricated by direct ultraviolet photolithography and wet etching processes. The experiment results show that the switch has a low switching power of 6.9 mW and a switching time of 0.4 ms.
A 32 × 32 arrayed waveguide grating (AWG) multiplexer operating around the 1550 nm wavelength has been designed and fabricated using fluorinated poly (ether ether ketone). The schematic layout is about 3.2×1.7 cm2. For our AWG, the total loss of designed AWG multiplexer is calculated to be 4.5 dB. We fabricated the AWG multiplexer by spin coating, photolithographic patterning and reactive ion etching (RIE). The core size is 5×5 μm2. The roughness of polymer surface was reduced by 20 nm using a remelting technique. The measured wavelength channel spacing of the fabricated AWG multiplexer is 0.796 nm and center wavelength is 1548 nm. The inserting loss of the AWG is 9.5 dB and crosstalk less than -20 dB.
In this paper, the basic principle, details of fabricating process and measuring results were described for a polymer/Si arrayed waveguide grating (AWG) multiplexer around the central wavelength of 1.550 micron with the wavelength spacing of 1.6nm. The fluorinated polymer was used to fabricate AWG to reduce the optical loss, but the fluorinated material was expensive, so we initially adopted the polymer of polymethylmethacrylate(PMMA) type to go on technologic research. The regulated curve of refractive index was given for the core polymer. In order to obtain better shape of the waveguide after the reactive ion etching (RIE) using oxygen, an aluminum film as mask was used on polymer instead of conventional photoresist as mask. In order to reduce radiation loss of underciadding layer to Si
substrate, the underciadding layer thickness was increased to 11 micron through two times of spin-coating, thus the radiation loss was reduced to the order of 0.001dB. The measuring results indicates fabricated optical waveguide achieved single-mode transmission.
In this paper, a 9 X 9 Polymer/Si AWG was designed and fabricated. The cladding material is poly-methyl-methacrylate-co-glyciclyl methacrylate (PMMA-GMA) and the core material is the mixture of
PMMA-GMA and bis-phonel-A epoxy. During the fabrication process of the Polymer/Si AWG device, We used aluminum as mask on polymer instead of conventional photoresist as mask. The results show that the device is good for the wavelength division multiplexing (WDM) system. The output characteristics of the device were measured by a system based on the tapered fiber. The results show that our polymer/Si AWG meets the designed device well.
Based on the arrayed waveguide grating (AWG) multiplexer theory, some important parameters are optimized for the structural design of a polymer AWG multiplexer around the central wavelength of 1.55μm with the wavelength spacing of 1.6 nm. These parameters include diffraction order, focal length of slab waveguides, number of arrayed waveguides are determined. Then, a schematic waveguide layout of this device is presented, which contains 9 input and 9 output channels. The transmission and loss characteristics are analyzed. The computed results show that when we select the core thickness as 4 micron, width as 6 micron, pitch of adjacent waveguides as 26 micron, diffraction order number as 78, distance between the focal point and the origin as 8340 micron, the total loss of the device can be dropped to about 5.7dB, and the crosstalk among output channels can be dropped below -50dB.