The purpose of this thesis is to fabricate the quantum dot waveguide and measure electro-optic (EO) modulation characteristics. We focus on the refractive index change (£Gn), phase retardation, and electro-optic coefficients for quantum dot samples. The £fg=1.3£gm InGaAs quantum dot structures were grown on n+ GaAs substrates by MBE.
We design a series of 2.2£gm straight and slope 7¢X single mode waveguide, and use the cleavage surface method to produce Fabry-Perot cavity. In fabrication process, we first defined the device pattern by using photo-lithography technique. Second, we etched ridge waveguide by using dry etching or multi-step wet etching method. Finally, we used the etching solution HBr:HCl:H2O2:H2O=5:4:1:70 to smooth the sidewall and reduce the scattering loss.
We analyzed the quantum dot EO properties by measuring phase retardation of Fabry-Perot resonance at different bias. From measuring the Fabry-Perot resonance at£f=1515nm TE-polarization, the linear electro-optic (LEO) and quadratic electro-optic (QEO) coefficients of C311 sample are 7.26¡Ñ10-12m/v and 1.14¡Ñ10-18m2/v2 , respectively. And the LEO and QEO coefficients of C251 sample are 2.99¡Ñ10-11m/v and 4.10¡Ñ10-17m2/v2, respectively. By coupling £f=1515nm TM-polarized light, we found the main influence of C251 sample is Kerr effect, and the QEO coefficient is 3.52¡Ñ10-17m2/v2. Both electro-optic coefficients are significantly larger than those measured in quantum wells and bulk GaAs. These results are applicable to QD-based low drive voltage and small size modulators.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0730109-142937 |
| Date | 30 July 2009 |
| Creators | Kuo, Chao-yi |
| Contributors | Tien-Tsorng Shih, Mau-Phon Houng, Tsong-Sheng Lay, Yi-Jen Chiu, Wood-Hi Cheng |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0730109-142937 |
| Rights | not_available, Copyright information available at source archive |
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