Optical Processing Devices for Optical Communications: Multilayered a-SiC:H Architectures
- PDF / 537,712 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 29 Downloads / 207 Views
1153-A19-01
Optical Processing Devices for Optical Communications: Multilayered a-SiC:H Architectures P. Louro1,2, M. Vieira1, M. A. Vieira1, M. Fernandes1, A. Fantoni1, G. Lavareda2, C.N. Carvalho3. Electronics Telecommunication and Computer Dept. ISEL, R. Conselheiro Emídio Navarro, 1949-014 Lisboa, Portugal Tel: +351218317290, Fax:+351218317114, [email protected], 2 CTS-UNINOVA, Monte da Caparica, 2829-516, Portugal. 3 ICEMS, IST, Av. Rovisco Pais, 1049-001, Lisboa, Portugal
1
ABSTRACT In this paper three multilayered architectures based on a-SiC:H with voltage controlled spectral selectivity in the visible spectrum range are analyzed. Multiple simultaneous modulated communication channels (red, green and blue or their polychromatic mixtures) were transmitted together at different frequencies. The combined optical signal was analyzed by reading out the photocurrent signal generated by the devices, under different applied voltages. Results show that the multiplexed signal depends on the device architecture and is balanced by the wavelength and transmission speed of each input channel, keeping the memory of the incoming optical carriers. In the single graded p-i’i-n configuration the device acts mainly as an optical switch while in two stacked p-i’-n-(ITO)-p-i-n configurations, the input channels are selectively tuned by shifting between forward and reverse bias. An electrical model, supported by a numerical simulation gives insight into the device operation. INTRODUCTION Wavelength division multiplexer (WDM) is a standard technique used in optical communications to enlarge the bandwidth of the transmission channel. For its implementation it is necessary to use a multiplexer device to combine multiple signals into the optical fiber and a demultiplexer device to perform the splitting of the combined signals into the original ones. In long distance communications the infrared window is used in the WDM technique [1]. In short range communications the transmission window lays within the visible spectrum, and thus the multiplexer and demultiplexer devices must operate in this range which demands for the design of adequate mux/demux devices [2, 3]. Some of the applications related to short range optical communication [4] include short range networking, e.g. indoor and LAN applications, the auto industry, consumer electronics, and the medical imaging for image-transfer applications. In this paper we present a series of wavelength sensitive transducers working as voltage controlled optical filters and optimized to take advantage of the whole visible spectrum. DEVICE ARCHITECTURE pin 1 (a-SiC:H)
pin 2 (a-Si:H)
TCO
TCO
n
GLASS
i (a-Si:H)
TCO
TCO
GLASS
i’ p (a-SiC:H)
200 nm 1000 nm b) a) Figure 1 - WDM device architecture: a) pi’in stucture with graded intrinsic layer (NC11); b) stacked pi’n/pin structure (NC10).
200 nm
1000 nm
The semiconductor sensor element is based on single or stacked a-SiC:H p-i-n structures using different architectures, as depicted in Fig. 1. All devices were produced by PE-CVD
Data Loading...
