A. Payusov

81 fJ/bit energy-to-data ratio of 850 nm vertical-cavity surface-emitting lasers for optical interconnects

Extremely energy-efficient oxide-confined high-speed 850 nm vertical-cavity surface-emitting lasers for optical interconnects are presented. Error-free performance at 17 and 25 Gb/s via a 100 m multimode fiber link is demonstrated at record high dissipation-power-efficiencies of up to 69 fJ/bit (<0.1u2002mW/Gbps) and 99 fJ/bit, respectively. These are the most power efficient high-speed directly modulated light sources reported to date. The total energy-to-data ratio is 83 fJ/bit at 25u2009°C and reduces to 81 fJ/bit at 55u2009°C. These results were obtained without adjustment of driving conditions. A high D-factor of 12.0u2002GHz/(mA)0.5 and a K-factor of 0.41 ns are measured.

99 fJ/(bit

We present extremely energy-efficient oxide-confined 850-nm single-mode vertical-cavity surface-emitting lasers (VCSELs) for optical interconnects. Error-free transmission at 17 Gb/s across 1 km of multimode optical fiber is achieved with an ultra-low energy-to-data ratio of 99 fJ/bit, corresponding to a record-low energy-to-data-distance ratio of 99 fJ/(bit ·km). This performance is achieved without changing any of the driving parameters up to 55 °C. To date our VCSELs are the most energy-efficient directly modulated light-sources for data transmission across all distances up to 1 km of multimode optical fiber.

\cdot

We present multioxide-aperture 980 nm-range vertical cavity surface emitting lasers (VCSELs) with highly temperature stable modulation characteristics operating error-free at 25 Gbit/s at 25 and 85u2009°C. We perform small signal modulation experiments and extract the fundamental physical parameters including relaxation resonance frequency, damping factor, parasitic cut-off frequency, D-factor, and K-factor, leading to identification of thermal processes and damping as the main factors that presently limit high speed device operation. We obtain very temperature-insensitive bandwidths around 13–15 GHz. Presented results clearly demonstrate the suitability of our VCSELs for practical and reliable optical data transmission systems.

km) Energy to Data-Distance Ratio at 17 Gb/s Across 1 km of Multimode Optical Fiber With 850-nm Single-Mode VCSELs

Highly energy-efficient oxide-confined 850-nm singlemode vertical-cavity surface-emitting lasers (VCSELs) for optical interconnects are presented. Error-free (defined as a bit error ratio <; 1 × 10-12) data transmission at 17 and 25 Gb/s across 100 m of multimode optical fiber is achieved with a low dissipated heat energy of only 69 and 99 fJ/bit, respectively. At 17 and 25 Gb/s, the transmission distance is increased to 1000 and 600 m, respectively. To date, our VCSELs are the most energy-efficient directly modulated lasers for data transmission across distances up to 1 km of multimode optical fiber.

Highly temperature-stable modulation characteristics of multioxide-aperture high-speed 980 nm vertical cavity surface emitting lasers

Single mode (SM) 850 nm vertical-cavity surface-emitting lasers (VCSELs) are suitable for error-free (bit error ratio <10-12) data transmission at 17-25 Gb/s at distances ~2-0.6 km over 50μm-core multimode fiber (MMF). Reduced chromatic dispersion due to ultralow chirp of SM VCSELs under high speed modulation (up to 40 Gb/s) are responsible for the dramatic length extension. Good coupling tolerances of the SM devices to the MMF manifest their applicability for low cost optical interconnects. As the higher resonance frequency (up to 30 GHz) is reached at lower current densities in small aperture (3 μm -diameter) devices the SM devices are also preferable due to reliability considerations.

Energy-Efficient Oxide-Confined 850-nm VCSELs for Long-Distance Multimode Fiber Optical Interconnects

Temperature-dependent lasing characteristics of transverse single-mode GaAs-based InAs submonolayer (SML) quantum-dot (QD) lasers are investigated. The SML QD lasers, when operated under continuous wave (cw) conditions up to 65°C, exhibit a high characteristic temperature (<i>T</i>₀) of around 101 K. The temperature-dependent net modal gain is also studied using the Hakki-Paoli method, yielding a narrow gain spectrum width of 15.6 meV at 20°C where the peak gain is 9.6 cm^-1. The lasers exhibit a low loss of -6 to -9 cm^-1 in the temperature range of 15°C to 65°C.

Progress on single mode VCSELs for data- and tele-communications

We demonstrate error-free 25 Gb/s optical interconnects with 850 nm vertical-cavity surface-emitting lasers. At 25°C through 100, 303, and 603 meters of fiber we achieve record heat-to-bit-rate ratios of 99, 122, and 188 mW/Tbps, respectively.

Temperature-Dependent Characteristics of Single-Mode InAs Submonolayer Quantum-Dot Lasers

We present 980-nm VCSELs with very temperature-insensitive bandwidth and highly stable 25 Gbit/s eye diagrams up to 85°C, confirming the suitability of our VCSELs for practical very short reach optical interconnects.

Energy efficient 850 nm VCSELs operating error-free at 25 Gb/s over multimode optical fiber up to 600 m

State-of-the-art vertical-cavity surface-emitting laser (VCSEL) based optical interconnects for application in high performance computers and data centers are reviewed. Record energy-efficient data transmission is demonstrated with 850 nm single-mode VCSELs for multimode optical fiber lengths up to 1 km at bit rates up to 25 Gb/s. Total power consumption of less than 100 fJ/bit is demonstrated for VCSELs for the first time. Extremely temperature stable 980-nm VCSELs show lasing up to 200 °C. Error-free 44 Gb/s operation at room temperature and 38 Gb/s up to 85 °C is achieved with these devices. We present record-high bit rates in a wide temperature range of more than 160 °C. Record energy-efficient data-transmission beyond 30 Gb/s is achieved at 25 °C for this wavelength range. In view of the high speed and advanced temperature stability we suggest long wavelength VCSELs for energy-efficient short and very short-distance optical interconnects for future high performance computers.

High-speed 980-nm VCSELs for very short reach optical interconnects

Record energy-efficient oxide-confined 850-nm single mode and quasi-single mode vertical-cavity surface-emitting lasers (VCSELs) for optical interconnects are presented. Error-free performance at 17 Gb/s is achieved with record-low dissipated power of only 69 fJ/bit. The total energy consumption is only 93 fJ/bit. Transmission lengths up to 1 km of multimode optical fiber were achieved. Our commercial quasi-single mode devices achieve error-free operation at 25 Gb/s across up to 303 m of multimode fiber. To date our VCSELs are the most energy-efficient directly modulated light-sources at any wavelength for data transmission across all distances up to 1 km of multimode optical fiber.