|Publication No: 2979||Search all ORC publications|
New method to fabricate ZnS optical waveguides using thermoelectric devices
Saafie Salleh, M.N.Dalimin, Abdullah Chik and H.Rutt*
School of Science and Technology, Universiti Malaysia Sabah, Locked Bag 2073, 88999 Kota Kinabalu, Sabah.
* Optoelectronics Research Centre, University of Southampton, UK
This work describes a new method to fabricate ZnS thin films using the thermal evaporation technique with a low substrate temperature. This work also was undertaken to establish that cold substrate evaporation using thermo electric coolers could be utilised to produce ZnS waveguides. A thermoelectric device which could be used to both heat and cool the substrates was designed and employed to deposit ZnS thin films on polished glass and silicon wafers. The in-situ heating and cooling were important factors to ensure that the ZnS films deposited on cold substrates show low loss waveguide characteristics. Optimizing this polycrystalline waveguide fabrication was a considerable challenge compared to the established, conventional waveguide fabrication. Propagation mode and power loss measurement were done by a commercial prism coupling method which is fitted with He-Ne laser and diode lasers. The transverse electric mode (TE) and loss decrease when the wavelength is increased. These observations agree well with a Rayleigh scattering model of the loss mechanism. The lowest loss of polycrystalline ZnS waveguide is 2.23 dB/cm measured a wavelength of 1540 nm.
20th Regional Conference on Solid State Science & Technol. Lumut, Perak, Malaysia 12-14 Dec (2003)
Copyright University of Southampton 2006