TY - JOUR
T1 - Thin-film lithium niobate-on-insulator waveguides fabricated on silicon wafer by room-temperature bonding method with silicon nanoadhesive layer
AU - Takigawa, Ryo
AU - Asano, Tanemasa
N1 - Funding Information:
Japan Society for the Promotion of Science (JSPS) KAKENHI (JP17H04925).
PY - 2018/9/17
Y1 - 2018/9/17
N2 - Lithium niobate-on-insulator (LNOI) waveguides fabricated on a silicon wafer using a room-temperature bonding method have potential application as Si-based high-density photonic integrated circuits. A surface-activated bonding method using a Si nanoadhesive layer was found to produce a strong bond between LN and SiO2/Si at room temperature, which is sufficient to withstand both the wafer-thinning (LN thickness <5 μm) and surface micromachining processes used to form the strongly confined waveguides. In addition, the bond quality and optical propagation characteristics of the resulting LNOI waveguides were investigated, and the applicability of this bonding method to low-loss LNOI waveguide fabrication is discussed. The propagation loss for the ridged waveguide was approximately 2 dB/cm at a wavelength of 1550 nm, which was sufficiently low for the device application. The results of the present study will be of significant use in the development of fabrication techniques for waveguides with any bonded materials using this room-temperature bonding method, and not only LN core/SiO2 cladding waveguides.
AB - Lithium niobate-on-insulator (LNOI) waveguides fabricated on a silicon wafer using a room-temperature bonding method have potential application as Si-based high-density photonic integrated circuits. A surface-activated bonding method using a Si nanoadhesive layer was found to produce a strong bond between LN and SiO2/Si at room temperature, which is sufficient to withstand both the wafer-thinning (LN thickness <5 μm) and surface micromachining processes used to form the strongly confined waveguides. In addition, the bond quality and optical propagation characteristics of the resulting LNOI waveguides were investigated, and the applicability of this bonding method to low-loss LNOI waveguide fabrication is discussed. The propagation loss for the ridged waveguide was approximately 2 dB/cm at a wavelength of 1550 nm, which was sufficiently low for the device application. The results of the present study will be of significant use in the development of fabrication techniques for waveguides with any bonded materials using this room-temperature bonding method, and not only LN core/SiO2 cladding waveguides.
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U2 - 10.1364/OE.26.024413
DO - 10.1364/OE.26.024413
M3 - Article
C2 - 30469560
AN - SCOPUS:85053395528
VL - 26
SP - 24413
EP - 24421
JO - Optics Express
JF - Optics Express
SN - 1094-4087
IS - 19
ER -