In the above paper (ibid., vol. 50, no. 8, pp. 613-621, Aug. 2014), the sixth author was misidentified. His name should have read James A. Lott in the byline and in his biography.

Highly temperature stable, high bit rate oxide-confined vertical-cavity surface-emitting lasers (VCSELs) emitting at 980 nm are presented. Error-free data transmission at 38 Gb/s at 25 °C, 45 °C, 65 °C, and 85 °C is achieved without any change of working point and modulation condition. Static and high-speed properties are analyzed experimentally and theoretically. We numerically investigate the temperature dependence of the differential gain of our quantum well (QW) active region design to explain why a -15-nm QW gain-to-etalon wavelength offset facilitates our 980-nm VCSELs to show simultaneously high bit rate, temperature stability, and energy efficiency. Our VCSELs operate error-free at 42 and 38 Gb/s at 25 °C and 85 °C, respectively, with very low power consumption. Record low 175 fJ of dissipated heat per bit is achieved for 35-Gb/s error-free transmission at room temperature and 177 fJ/bit for 38-Gb/s error-free transmission at 85 °C. Such VCSELs are especially well suited for very-short-reach (<;1 m) optical interconnects in high-performance computers and board-to-board and chip-to-chip integrated photonics.

980 nm vertical-cavity surface-emitting lasers (VCSELs) operating error-free at 38 Gbit/s at 85°C with record 177 fJ of dissipated heat per bit are presented. The VCSELs are particularly well suited for short, very-short and ultra-short-reach interboard, chip-to-chip and intrachip optical interconnects, where temperature stability, bandwidth and VCSEL density and the minimisation of waste heat are critical. Error-free operation at 40 Gbit/s at 75°C and at 42 Gbit/s at 25°C is achieved. To date, 980 nm VCSELs are the most energy-efficient of all VCSELs at 85°C at any wavelength.

Extremely temperature stable oxide-confined high-speed 980-nm vertical-cavity surface-emitting lasers (VCSELs) for optical interconnects are presented. Error-free performance at 38 Gb/s and 40 Gb/s is demonstrated at temperatures as high as 85 °C and 75 °C, respectively. No adjustment of driving conditions was found to be necessary from room temperature up to 85 °C. In addition, energy-efficient 35 Gb/s operation at a very low pump current of only 4 mA is demonstrated with a low dissipated heat-to-bit rate ratio of 233 mW/Tbps. These are by far the highest bit rates reported for VCSELs at such temperatures.

Optical and electrical investigations of vertical-cavity surface-emitting lasers (VCSEL) with a monolithically integrated electro-optical modulator (EOM) allow for a detailed physical understanding of this complex compound cavity laser system. The EOM VCSEL light output is investigated to identify optimal working points. An electro-optic resonance feature triggered by the quantum confined Stark effect is used to modulate individual VCSEL modes by more than 20 dB with an extremely small EOM voltage change of less than 100 mV. Spectral mode analysis reveals modulation of higher order modes and very low wavelength chirp of < 0.5 nm. Dynamic experiments and simulation predict an intrinsic bandwidth of the EOM VCSEL exceeding 50 GHz.

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.

Results of a comparative study of the structural parameters and the static and dynamic characteristics of vertical-cavity surface-emitting lasers (VCSELs) with microresonators based on Al 0.15 Ga 0.85 As and Al 0.8 Ga 0.2 As are presented. It is established that the vertical oxidation of layers in the Al 0.8 Ga 0.2 As microresonator during formation of the current aperture leads to a significant increase in the oxide thickness. This leads to a considerable decrease in parasitic capacitance of the device and a 1.7- to 2-fold growth in the cut-off frequency of a low-frequency filter formed by parasitic elements of the equivalent electric scheme of the device.

High-performance vertical-cavity surface-emitting lasers are presented. These lasers are optimized for application in optical interconnects at highest data-rates and highest operation temperatures. Error-free performance at 49 Gb/s and 12.5 Gb/s at 155 °C were achieved.

High-performance vertical-cavity surface-emitting lasers optimised for highest data rates and operating temperatures are presented. Error-free performance at bit rates up to 47 Gbit/s or temperatures up to 155°C is demonstrated. These are the highest ratings reported to date.

We present our recent theory and experiment of metal-cavity microlasers and nanoLEDs on silicon substrates with electrical injection at room temperature.

Progress of high-speed vertical cavity surface emitting lasers (VCSEL) operating around 980 nm is reviewed. A special focus is on their applications for future short-reach optical interconnects, for example, in high-performance computers (HPC). The wavelength of 980 nm has fundamental advantages for these applications and plays a significant role in VCSEL research today. The present data rates of 980 nm VCSELs exceed 40 Gbit/s, and excellent temperature stability has been reported. The major concepts leading to these impressive developments are presented.

As the density of transistors in CMOS integrated circuits continues to roughly double each two years the processor computational power also roughly doubles. Since the number of input/output (I/O) devices can not increase without bound I/O speed must analogously approximately double each two years. In the Infiniband EDR standard (2011) a single channel bit rate of 26 Gb/s is foreseen. The maximum reliable and efficient copper link length shrinks at bit rates above 10 Gb/s to a few meters at best. At higher bit rates the length of a given multimode fiber link must also shrink, due to both modal and wavelength dispersions. Although the modal dispersion in modern multimode OM3 and OM4 fibers that are optimized for 850 nm vertical-cavity surface-emitting lasers (VCSELs) is reduced, the wavelength dispersion remains a serious issue for standard multimode VCSELs. An ultimate solution to overcome this problem is to apply single-mode VCSELs to extend and ultimately maximize the link length. In this paper we demonstrate recent results for single-mode VCSELs with very high relaxation resonance frequencies. Quantum well 850 nm VCSELs with record high 30 GHz resonance frequencies are demonstrated. Additionally single-mode data transmission at 35 Gb/s over multimode fiber is demonstrated. For comparison we also present specific device modeling parameters and performance characteristics of 850 nm single-mode quantum dot (QD) VCSELs. Despite a significant spectral broadening of the QD photoluminescence and gain due to QD size dispersion we obtain relaxation resonance frequencies as high as 17 GHz.

For future applications of semiconductor lasers in LAN/SAN, to increase the maximum achievable bit rate at room temperature becomes the ultimate goal and challenge, while the importance of the high temperature stability of the laser properties plays a smaller role, as compared to application for on-chip, chip-to-chip and module-to-module data transmission. From the other side, there are optical standards which define the wavelength of 850 nm to be used for data transmission in LAN/SAN, thus the freedom to choose any desired wavelength is no more present. Consequently, to meet the requirements for the future LAN/SAN optical data transmission, cheap and robust VCSELs emitting around 850 nm with the highest possible data transmission bit rate should be realized. According to the coming standards, lasers with the bit rate of 30 Gbit/s and larger are necessary in the next several years. Additionally, optics is coming also to shorter distances and in the near future definitively will replace copper-based data transmission lines for such application like, for example, data communication between a personal computer and portable devices (USB stick, mp3 player, etc.), between computer and monitor, between TV and player, etc. These application fields require semiconductor lasers capable to a very cheap mass production, and VCSELs are practically the only suitable candidates.

It has been shown that the use of submonolayer InAs insertions as an active region of AlGaAs vertical cavity surface emitting lasers make it possible to attain resonant frequencies as high as 17 GHz. In this case, single-mode devices with a smaller diameter of the current aperture make it possible to attain higher frequencies at lower current densities than those of multimode devices with a larger aperture diameter. The maximum error-free data transmission rate in the direct modulation mode in NRZ format is 20 Gb/s and is limited by the parasitic cutoff frequency. The high resonant frequency suggests that further optimization of the device design, directed to decreasing the electrical capacitance and resistances, the data transmission rate in lasers based on submonolayer insertions can be increased to 40 Gb/s.

We present 980 nm VCSELs operating error free at a bit rate of 25 Gbit/s at temperatures of up to 85 °C. These devices are advantageous for future optical interconnects in high performance computer applications.

The ever growing demand for more bandwidth in high-performance computing (HPC) applications leads to a continuous replacement of traditional copper-based links by optical interconnects at ever shorter transmission distances. However, this trend results in a more stringent performance requirements for laser light sources utilized in new generations of optical interconnects in respect to single channel speed, packaging density, power consumption and temperature stability, to make the technology competitive and commercially viable. Vertical cavity surface emitting lasers operating at different wavelengths, e. g. 850 or 980 nm, represent one possible solution for the short distance high density interconnects in HPC applications. Here we present ultra-high speed highly temperature stable 980 nm VCSELs operating error-free at the record high bit rate of 44 Gbit/s at room temperature and 38 Gbit/s at 85 °C for future inter-and intra-chip, and module-to-module optical links. Next we present high speed extremely energy efficient 850 nm VCSELs with record low energy consumptions of only 83 fJ/bit while operating at 17 Gbit/s and of only 117 fJ/bit at 25 Gbit/s. Our VCSELs enable ecologically sound and economically practical HPC designs.

We demonstrate a metal-cavity surface-emitting microlaser at room temperature using hybrid metal/distributed Bragg reflectors as well as substrate removal. Our devices operate under continuous-wave current injection at room temperature. The smallest laser is 1.0 μm in radius and ~4.0 μm in height with a circular beam shape and an output over 8 μW. The device lases at 995 nm wavelength with a threshold current of about 2.6 mA.

Highly temperature-stable, high-speed 980-nm VCSELs for optical interconnects are presented. Error-free performance up to 44 Gb/s at 25°C and 38 Gb/s at 85°C is demonstrated. These are the highest data-rates for VCSELs reported to date.