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Scanning electron microscope image of an ETR laser with 20-m sides. (a) Side view of the resonator, (b) close-up view of one of the vertices, and (c) top-down view of a mounted ETR laser with a connected gold wire.
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Equilateral-triangle-resonator (ETR) microlasers with an output waveguide connected to one of the vertices of the ETR are suitable to be a light source for photonic integrated circuits. InP-GaInAsP ETR lasers with side length from 10 to 30 mum and the output-waveguide width of 1 or 2 mum are fabricated using standard photolithography and inductivel...
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... HF solution. Finally, a 300-nm SiO insulating layer is deposited and a contact window is opened on top of each ETR pattern using the wet etching process. A top Ti-Au p-contact is formed using standard metal deposition and the wafer is lapped down to a thickness of about 100 m, and an Au-Ge-Ni-Au metallization is used for the n-type contacts. Fig. 1(a) shows an ETR with an output waveguide formed after the ICP and chemical etching, and Fig. 1(b) is a closer view of one of the vertices of the ETR with slightly rounded vertices mainly due to pattern distortion during photolithography and the chemical etching process. Fig. 1(c) is a top-down view of a mounted InP-GaInAsP ETR laser, ...
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... on top of each ETR pattern using the wet etching process. A top Ti-Au p-contact is formed using standard metal deposition and the wafer is lapped down to a thickness of about 100 m, and an Au-Ge-Ni-Au metallization is used for the n-type contacts. Fig. 1(a) shows an ETR with an output waveguide formed after the ICP and chemical etching, and Fig. 1(b) is a closer view of one of the vertices of the ETR with slightly rounded vertices mainly due to pattern distortion during photolithography and the chemical etching process. Fig. 1(c) is a top-down view of a mounted InP-GaInAsP ETR laser, which is cleaved across the output coupling waveguide for measuring output power and lasing ...
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... m, and an Au-Ge-Ni-Au metallization is used for the n-type contacts. Fig. 1(a) shows an ETR with an output waveguide formed after the ICP and chemical etching, and Fig. 1(b) is a closer view of one of the vertices of the ETR with slightly rounded vertices mainly due to pattern distortion during photolithography and the chemical etching process. Fig. 1(c) is a top-down view of a mounted InP-GaInAsP ETR laser, which is cleaved across the output coupling waveguide for measuring output power and lasing spectrum. A bounded gold wire can be found on the right side of the ...
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Citations
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AlGaInAs/InP hexagonal resonator microlasers with an output waveguide connected to one vertex of the hexagon are fabricated using standard photolithography and inductively coupled plasma (ICP) etching process. Room-temperature continuous-wave electrically injected operation with a threshold current of 18 mA is realized for a hexagon laser with an edge length of 16 � m and an output waveguide width of 2 � m. Single-mode operation is achieved with a side mode suppression ratio of 21 and 33 dB at the injection current of 30 and 60 mA, respectively. The peak wavelength intervals of the laser spectrum agree very well with the longitudinal mode intervals of the whispering-gallery modes, which indicates single transverse mode operation. The modeQ factor of 6:53 � 10 3 is measured for the lasing mode at 1547 nm at the threshold current, which is in the same magnitude as the Q factor obtained by finite-difference time-domain (FDTD) simulation. The numerical simulations also indicate that the hexagonal resonator with an output waveguide is suitable to realize single transverse mode operation.
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AlGaInAs-InP microcylinder lasers connected with an output waveguide are fabricated by planar technology. Room-temperature continuous-wave operation with a threshold current of 8 mA is realized for a microcylinder laser with the radius of 10 μm and the output waveguide width of 2 μm. The mode Q -factor of 1.2 x 10<sup>4</sup> is measured from the laser spectrum at the threshold. Coupled mode characteristics are analyzed by 2-D finite-difference time-domain simulation and the analytical solution of whispering-gallery modes. The calculated mode Q -factors of coupled modes are in the same order as the measured value.
... Furthermore, microdisk lasers vertically coupled with a bus waveguide were realized by wafer bonding technique [9], [10] . Recently, room-temperature continuous-wave (CW) electrically injected InGaAsP–InP triangle and square microlasers were fabricated with an output waveguide connected to the resonator [11], [12]. The triangle and square resonators are laterally confined by insulator SiO and -electrode metals on etched sidewalls, which greatly affect the mode factor [13], [14], and up to six transverse modes are observed in a square microlaser with the side length of 20 m [15]. ...
InGaAsP-InP square microlasers with a vertex output waveguide are fabricated by planar processes, and the etched sidewalls of the lasers are confined by insulating layer SiO<sub>2</sub> and p-electrode Ti-Au metals. For a square microlaser with a side length of 30 μm and a 2-μm -wide output waveguide, a continuous-wave threshold current is 26 mA at room temperature and output power is 0.72 mW at 86 mA. The mode interval of 21 and 7.4 nm is observed for the microlasers with the side length of 10 and 30 μm , respectively. Finite-difference time-domain (FDTD) simulations indicate that the lasing modes have incident angles of about 45 <sup>°</sup> at the boundaries of the resonator. In addition, square resonators surrounded by air, SiO<sub>2</sub>-Ti-Au, and SiO<sub>2</sub>-Au are compared by FDTD simulations.
