Oxide-Relief and Zn-Diffusion 850-nm Vertical-Cavity Surface-Emitting Lasers With Extremely Low Energy-to-Data-Rate Ratios for 40 Gbit/s Operations

Abstract

We demonstrate novel structures of a vertical-cavity surface-emitting laser (VCSEL) for high-speed (∼40 Gbit/s) operation with ultralow power consumption performance. Downscaling the size of oxide aperture of VCSELs is one of the most effective ways to reduce the power consumption during high-speed operation. However, such miniaturized oxide apertures (∼2 μm diameter) in VCSELs will result in a large differential resistance, optical single-mode output, and a small maximum output power (< 1 mW). These characteristics seriously limit the maximum electrical-to-optical (E-O) bandwidth and device reliability. By the use of the oxide-relief and Zn-diffusion techniques in our demonstrated 850-nm VCSELs, we can not only release the burden imposed on downscaling the current-confined aperture for high speed with low-power consumption performance, but can also manipulate the number of optical modes inside the cavity to maximize the E-O bandwidth and product of bit-rate transmission distance in an OM4 fiber. State-of-the-art dynamic performances at both room temperature and 85 • C operations can be achieved by the use of our device. These include extremely high D-factors (∼13.5 GHz/mA 1 /2 ), as well as record-low energy-to-data ratios (EDR: 140 fJ/bit) at 34 Gbit/s operation, and error-free transmission over a 0.8-km OM4 multimode fiber with a record-low energyto-data distance ratio (EDDR: 175.5 fJ/bit.km) at 25 Gbit/s.

Review on Single-Mode Vertical-Cavity Surface-Emitting Lasers for High-Speed Data Transfer

“…For the next generation of VCSELs, where InGaAlAs was used as an active region, effective modulation frequencies at the level of 15-25 GHz [81,[85][86][143][144] with a limiting value of 30 GHz [139] for 850 nm VCSELs became ordinary. As for LW VCSELs, maximum achieved values were 19 and 22 GHz, respectively [112].…”

Single-Mode Vertical-Cavity Surface-Emitting Laser Array With High Power and Narrow Far-Field Divergence Angle

“…1(a), the fabricated device has a $34 m diameter active mesa, and the n-type contact is realized on the bottom side of n-type GaAs substrate in order to uniform the current distribution especially in the array structure. The epitaxy-layer is the standard 850 nm VCSEL epi-layer structure (IEGENS-7-20) purchased from IQE, and the detail device fabrication processes and epi-layer structure can be referred to our previous work [6], [11], [22]. Fig.…”

“…Vertical-cavity surface-emitting lasers (VCSELs) [1] have attracted much attention due to their several unique advantages, such as two-dimensional (2-D) array formation [2], [3], inexpensive device fabrication, and on-wafer characterization. High-output-power, high modulation speed, and a single-lobe (spot) output with a low divergence angle and circular symmetry far-field pattern of VCSEL are much desired for several applications, such as (free space) optical interconnects [4]- [6], laser printing, laser mouse [7], airborne light detecting and ranging (LIDAR) systems [8], and infrared lighting [9]. Increasing the effective diameter of the circular light-emitting aperture of a VCSEL is necessary to achieve a high output power.…”

Infrared Vertical-Cavity Surface-Emitting Lasers with a Multi-Oxide Layer Structure: Small Change Big Effect

“…Beside electrical parasitic circuit effects such as : parasitic top and bottom mirrors resistances and parasitic junction, oxide, and pad capacitances [6]- [10], and thermal effects due to self-heating [8], [10] characteristics including multi-mode operation [10], [14], [15] can also limit the VCSEL's performance and thus limits the utilization of VCSELs in several potential applications such as high-speed laser printing and engraving, bar code scanning, and single-mode optical fiber data communication.…”