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We demonstrate a 1.55-/spl mu/m InAlGaAs/InP vertical-cavity surface-emitting laser grown by metal-organic chemical vapor deposition. AI/sub 2/O/sub 3/-Si thin-film pairs and InAlGaAs/InAlAs epitaxial layers are used as a top mirror and a bottom-side output coupler, respectively. Direct modulation characteristics through single mode fiber are reported in the speed of 2.5 Gbit/s.

We demonstrate continuous wave operation of MOCVD-grown 1.55 /spl mu/m buried tunnel junction VCSELs at room temperature. This buried tunnel junction VCSEL structure is prepared by MOCVD twofold epitaxial growth. The threshold current and emission wavelength for a 10 /spl mu/m-diameter device are 3.5 mA and 1552 nm, respectively.

We proposed a new type of 1550 nm VCSEL incorporating proton implantation and a dielectric mirror. Even though it suffers from poor heat removal rate, it could be a promising structure since the structure and fabrication scheme rely on stable material and well-established processing techniques. The fabricated laser operates under pulsed conditions emitting at 1550 nm. The use of flip-chip bonding and good choice of dielectric material may improve the overall laser performance.

Our photonic bandgap single defect laser structure is shown. For an active medium, six strain compensated InGaAsP quantum wells are employed because of the relatively small surface recombination velocity. To realize a mechanically-robust structure with good thermal properties, the InGaAsP layer was fused with the AlAs layer on top of a GaAs wafer. For optical confinement in the vertical direction, the top AlAs is wet-oxidized. After electron-beam lithography, the AlAs layer is etched by chemically-assisted ion-beam etching. The etched triangular lattice patterns form 2-D photonic bandgap cavities of various sizes having periodicity of 450 nm. The diameter of holes is 270 nm. The thickness of active layer sandwiched between air and the wet-oxidized AlAs layer is smaller than the 1/2 wavelength to obtain a single mode condition. The finished photonic bandgap cavity is optically pumped with a 980-nm diode laser beam focused to approximately 4 mm in diameter.

In this study, we demonstrated a wide tuning range wavelength-swept laser with a single semiconductor optical amplifier (SOA) at 1020 nm for ultrahigh resolution, Fourier-domain optical coherence tomography (UHR, FD-OCT). The wavelength-swept laser was constructed with an external line-cavity based on a Littman configuration. An optical wavelength selection filter consisted of a grating, a telescope, and a polygon scanner. Before constructing the optical wavelength selection filter, we observed that the optical power, the spectrum bandwidth, and the center wavelength of the SOA were affected by the temperature of the thermoelectric (TE) cooler in the SOA mount as well as the applied current. Therefore, to obtain a wide wavelength tuning range, we adjusted the temperature of the TE cooler in the SOA mount. When the temperature in the TE cooler was 9 °C, our swept source had a tuning range of 142 nm and a full-width at half-maximum (FWHM) of 121.5 nm at 18 kHz. The measured instantaneous spectral bandwidth (δλ) is 0.085 nm, which was measured by an optical spectrum analyzer with a resolution bandwidth of 0.06 nm. This value corresponds to an imaging depth of 3.1 mm in air. Additionally, the averaged optical power of our swept source was 8.2 mW. In UHR, FD/SS-OCT using our swept laser, the measured axial resolution was 4.0 μm in air corresponding to 2.9 μm in tissue (n = 1.35). The sensitivity was measured to be 93.1 dB at a depth of 100 μm. Finally, we obtained retinal images (macular and optic disk) and a corneal image.

We present all-monolithic InAlGaAs/InP vertical cavity surface emitting lasers (VCSELs) emitting wavelength of 1.3 µm grown by metal organic chemical vapor deposition (MOCVD). The devices with tunnel junction (TJ) and the air-gap aperture showed the performances as high as output power of 1.1 mW and as low as threshold current of 1.9 mA operating in single-mode at room temperature. We obtained the emitting transverse wavelength of 1333.1 nm with side mode suppression ratio (SMSR) of 40 dB, the continuous wave (CW) operation of temperature over 80°C, and modulation bandwidth exceeding 2.5 Gbit/s.

InAlGaAs/InP-based all-monolithic 1.3 /spl mu/m VCSELs operating continuous wave up to 18/spl deg/C are demonstrated. The whole structure is grown by a single step of MOCVD. Selective wet etching of an InP layer is used to form an air-gap aperture for the current confinement. The threshold current of an 8 /spl mu/m device at 15/spl deg/C is /spl sim/2.8 mA.

Low threshold power vertical-cavity surface-emitting lasers are fabricated by using low loss Al/sub x/O/sub y//GaAs mirrors as output couplers. A 5 /spl mu/m-aperture laser with a low threshold CW pump power of 1.4 mW at room temperature and a 16 /spl mu/m-aperture laser operating in CW mode up to 64/spl deg/C are produced.

This paper reports a novel micro/nano fabrication method for mass production of low-stressed silicon nitride (SiN) membrane nanopores with the precisely size-controlled 30 nm in diameter using an anisotropic reactive ion etching (ARIE) and nano-imprinting method, while maintaining compatibility with CMOS IC processes. Our method differs from that of Striemer group [1] in the specific membrane material, and Hien group [2] in the specific fabrication protocols. Micromachining protocols facilitate the accomplishing nanostructures to be used for separation of collections of particles. However, membrane fragility and complex fabrication prevents the use of ultrathin membranes for molecular separations. Here, we report a novel, simple and robust micro/nano fabrication method of strong SiN nanosieve membrane with the small, precise, and uniform nano-sized pore structures with a diameter of 30 nm.