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Transmission and Group Index for
Suspended Membrane Type-B PCWG
Collected Power, mW
Wavelength, nm
Figure 3.15: Transmission spectrum for a suspended membrane, W1,
Type-B PCWG.
It is obvious from the figure that the group index for the Type-B waveguide is fairly
consistent across the 85nm tunable laser range, as the free spectral ranges of the
resonances are uniform across the band. Again we used Equation 3.1 to calculate the
group index over the spectrum. The group index varies primarily between 4.5 and 5.5
with an average of about 5. This is in line with the calculated bandstructure shown in
Figure 3.14 that predicts a large frequency range over which the slope of the waveguide
dispersion curve is constant. The calculated group index for this structure is shown as a
function of normalized wavelength in Figure 3.16(a). We see that there is a very large,
flat region of the curve between the normalized frequencies 0.25 and 0.275. At a lattice
constant of 420nm, this equates to over 150nm of non-dispersive bandwidth. It is
Object Description
| Title | Silicon-based photonic crystal waveguides and couplers |
| Author | Farrell, Stephen G. |
| Author email | stephenf@usc.edu; sgfarrell@yahoo.com |
| Degree | Doctor of Philosophy |
| Document type | Dissertation |
| Degree program | Electrical Engineering |
| School | Viterbi School of Engineering |
| Date defended/completed | 2008-09-05 |
| Date submitted | 2008 |
| Restricted until | Unrestricted |
| Date published | 2008-10-20 |
| Advisor (committee chair) | O'Brien, John D. |
| Advisor (committee member) |
Dapkus, P. Daniel Steier, William Haas H., Stephan |
| Abstract | Most commercial photonics-related research and development efforts currently fall into one or both of the following technological sectors: silicon photonics and photonic integrated circuits. Silicon photonics [18] is the field concerned with assimilating photonic elements into the well-established CMOS VLSI architecture and IC manufacturing. The convergence of these technologies would be mutually advantageous: photonic devices could increase bus speeds and greatly improve chip-to-chip and board-to-board data rates, whereas photonics, as a field, would benefit from mature silicon manufacturing and economies of scale. On the other hand, those in the photonic integrated circuit sector seek to continue the miniaturization of photonic devices in an effort to obtain an appreciable share of the great windfall of profits that occur when manufacturing, packaging, and testing costs are substantially reduced by shrinking photonic elements to chip-scale dimensions. Integrated photonics companies may [12] or may not [34] incorporate silicon as the platform.; In this thesis, we seek to further develop a technology that has the potential to facilitate the forging of silicon photonics and photonic integrated circuits: photonic crystals on silicon-on-insulator substrates. We will first present a brief overview of photonic crystals and their physical properties. We will then detail a finely-tuned procedure for fabricating two-dimensional photonic crystal in the silicon-on-insulator material system. We will then examine transmission properties of our fabricated devices including propagation loss, group index dispersion, and coupling efficiency of directional couplers. Finally, we will present a description of a system for adiabatically tapering optical fibers and the results of using tapered fibers for efficiently coupling light into photonic crystal devices. |
| Keyword | photonics; photonic crystal; silicon; integrated photonics; SOI; optoelectronics; waveguides; couplers; optical fiber; tapered fiber; evanescent coupling; adiabaticity; silicon photonics |
| Language | English |
| Part of collection | University of Southern California dissertations and theses |
| Publisher (of the original version) | University of Southern California |
| Place of publication (of the original version) | Los Angeles, California |
| Publisher (of the digital version) | University of Southern California. Libraries |
| Provenance | Electronically uploaded by the author |
| Type | texts |
| Legacy record ID | usctheses-m1681 |
| Contributing entity | University of Southern California |
| Rights | Farrell, Stephen G. |
| Repository name | Libraries, University of Southern California |
| Repository address | Los Angeles, California |
| Repository email | cisadmin@lib.usc.edu |
| Filename | etd-Farrell-2433 |
| Archival file | uscthesesreloadpub_Volume32/etd-Farrell-2433.pdf |
Description
| Title | Page 69 |
| Contributing entity | University of Southern California |
| Repository email | cisadmin@lib.usc.edu |
| Full text | 58 1540 1560 1580 1600 1620 0.000 0.002 0.004 0.006 0.008 0.010 Transmission and Group Index for Suspended Membrane Type-B PCWG Collected Power, mW Wavelength, nm Figure 3.15: Transmission spectrum for a suspended membrane, W1, Type-B PCWG. It is obvious from the figure that the group index for the Type-B waveguide is fairly consistent across the 85nm tunable laser range, as the free spectral ranges of the resonances are uniform across the band. Again we used Equation 3.1 to calculate the group index over the spectrum. The group index varies primarily between 4.5 and 5.5 with an average of about 5. This is in line with the calculated bandstructure shown in Figure 3.14 that predicts a large frequency range over which the slope of the waveguide dispersion curve is constant. The calculated group index for this structure is shown as a function of normalized wavelength in Figure 3.16(a). We see that there is a very large, flat region of the curve between the normalized frequencies 0.25 and 0.275. At a lattice constant of 420nm, this equates to over 150nm of non-dispersive bandwidth. It is |
