2026-09-21T09:01:39Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/14614 2023-07-10 col_2142_5131 col_2142_8888 com_2142_5130 com_2142_8887 com_2142_234

Choquette, Kent D. Choquette, Kent D. Tan, Meng Peun 2010-01-06T16:19:43Z 2010-01-06T16:19:43Z 2010-01-06T16:19:43Z This work focuses on how to achieve high power, low threshold, and high efficiency single mode VCSELs. Various mechanisms that affect the differential quantum efficiency and threshold current of the proton-implanted and oxide-confined photonic crystal vertical-cavity surface-emitting lasers (VCSELs) are studied. Three degrees of freedom in designing the photonic crystal VCSELs to maximize the laser performance in terms of efficiency and threshold current are considered: the epitaxial structure, the relative size of the current aperture and the transverse optical mode, and the photonic crystal design. The theoretical background regarding the differential quantum efficiency and threshold current of the photonic crystal VCSELs is presented. Proton-implanted 850 nm VCSELs intended for high efficiency single mode lasing are fabricated and characterized, and then the experimental results are compared with the theories. It is found that spectral and spatial mode-gain overlap, optical loss, and thermal effects affect the laser efficiency and threshold current. The thermal effects also affect the dynamical change of differential quantum efficiency with the injected current. The epitaxial structure determines the spectral mode-gain overlap and the modal properties of the VCSELs, while the relative size of the current aperture and the optical mode sets the spatial mode-gain overlap factor. The photonic crystal air hole fill-factor has an impact on all the mechanisms mentioned above. By etching the photonic crystal into proton-implanted VCSELs, stronger index guiding is introduced and consequently the wide distribution of efficiency and threshold current between devices and the discontinuity in measured output power versus current are eliminated, and the threshold current is reduced. Single mode power of 2.5 mW is obtained from proton-implanted photonic crystal VCSELs. Item withdrawn by Mark Zulauf (zulauf@illinois.edu) on 2009-12-04T00:44:20Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 1 Tan_Meng Peun.pdf: 3003823 bytes, checksum: 308e8cfc2eea675365581b0333e402b1 (MD5) Made available in DSpace on 2010-01-06T16:19:43Z (GMT). No. of bitstreams: 3 Tan_Meng Peun.pdf: 3003837 bytes, checksum: b96282e2d6c004440ddf5edb50899a26 (MD5) license.txt: 4057 bytes, checksum: 9a17100e08aa4bc22b28327c56b53eab (MD5) 1_Tan_Meng Peun.pdf: 3003823 bytes, checksum: 308e8cfc2eea675365581b0333e402b1 (MD5) http://hdl.handle.net/2142/14614 en Copyright 2009 Meng Peun Tan Vertical-cavity surface-emitting laser (VCSEL) oxide-confined photonic crystal vertical-cavity surface-emitting laser (VCSEL) proton-implanted photonic crsytal vertical-cavity surface-emitting laser (VCSEL) single mode operation differential quantum efficiency threshold current. Improving the efficiency and threshold current of photonic crystal vertical-cavity surface-emitting lasers 2009-12 M.S. PHD:Electr & Computer Eng-UIUC 10KS1200PHD Electrical & Computer Eng 1933 Electrical & Computer Engr 1200 University of Illinois at Urbana-Champaign Thesis