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Title: Research Toward a Heterogeneously Integrated InGaN Laser on Silicon
A heterogeneously integrated InGaN laser diode (LD) on Si is proposed as a path toward visible wavelength photonic integrated circuits (PICs) on Si. Herein, InGaN films are vertically stacked on a TiO2waveguide (WG) fabricated on a Si wafer by bonding. In the light propagation direction, it is composed of a hybrid InGaN/TiO2section, a TiO2WG, an adiabatic taper, and mirrors that can form a cavity. As the refractive index of GaN is well matched with that of TiO2, the optical transverse mode extends to both the GaN and TiO2in a hybrid mode. Modes between a hybrid InGaN/TiO2and a pure TiO2WG can transfer with an adiabatic taper structure. The coupling loss is calculated to be less than 0.5 dB with fairly short taper length of 78 μm and tip width of 200 nm. GaN substrate removal and bonding are critical fabrication steps of this LD and PIC. The substrate removal is successfully done by photoelectrochemical etching. Although direct bonding of GaN wafers with thermal oxide on Si is successful, GaN epitaxial wafers are more difficult. An implication and remedy of this is discussed in terms of surface roughness of GaN epitaxial film.  more » « less
Award ID(s):
1725797
PAR ID:
10128954
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
physica status solidi (a)
Volume:
217
Issue:
7
ISSN:
1862-6300
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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