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VCSELVertical Cavity Surface Emitting Laserdiode
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A small introductionA single vertical-cavity surface-emitting laser (VCSEL) is the smallest commercial available semiconductor laser diode type. The acronym VCSEL is pronounced 'vixel.' Each individual Laser fits on a chip area smaller than 0.25 to 0.25 mm. Most of the area is used for electrical contacts and marking. The intrinsical diameter of the active laser is smaller then that of a human hair. This enables mass market production similar to the technology used in the silicon industry. Older laser diodes, called edge-emitting diodes, emit the light parallel to the boundaries between the semiconductor layers. In contrast, the VCSEL emits its coherent beam perpendicular to the layer boundaries. which result in a cylindrical beam vertically from the surface of a fabricated wafer. VCSELs have been constructed to emit light at 850 nanometers (nm) and 980 nm. These wavelengths correspond to wavelength in the near infrared (IR) portion of the electromagnetic spectrum. (The longest visible red is at approximately 780 nm.) At ULM-Photonics VCSEL emissions wavelenght between approx. 760 nm and 1000 nm are available. Optical fibers transmit energy most efficiently at wavelengths around 1550 nm. Materials used to manufacture VCSELs include Gallium Arsenide (GaAs), Aluminum Gallium Arsenide (AlGaAs), Indium Phosphide based semiconductors, quantum dots based mainly on Indum Gallium Arsenide (InGaAs) or Indium Arsenide (InAs), and Indium gallium arsenide nitride (InGaAsN). VCSELs or VCSEL have high performance and low cost advantages. The key features are:
VCSELs are emitter for fiber data communication at speeds much higher than 1Gbs for high performance systems like Gigabit Ethernet, Fiber Channel (Fibre Channel), and ATM markets. Through their integration with original equipment manufacturer's (OEM) systems design, the 850nm VCSELs provide enhanced performance benefits to a variety of applications, such as local area networks (LAN), local networks like fibre-to-the-home (FTTH, FTTX, FTTC, FTTD, FTTP); optical wireless, free space optics (FSO), telecommunication switches, optical storage, sensing applications, gas detection, absorption spetroscopy, integration in sensors for night vision (sensor for infrared nightvision) and detection, homeland security application like light barrier, photo-electric guard, photo sensor, photoelectric barrier and relay, military application like range finder and target localization, medical applications like low level laser therapy (LLLT), automotive datacom (e.g. MOST = Media Oriented Systems Transport; BYTEFLIGHT, IEEE 1394) over POF (plastic optical fiber), PCS (or PCF: polymer cladded fiber) or GOF (glass optical fiber by SCHOTT) with FOT (fiber optic transceiver) as used by BMW, Daimler Chrysler, Toyota and supported by Infineon, Oasis and Hamamatsu. Many other optoelectronic and lighting systems are possible and under development (like optical mouse). VCSELs are fabricated cost efficiently on a 3-inch diameter wafer. Due to the possibility to manufacture these VCSEL lasers by standard microelectronic fabrication techniques used in the silicon industry it is possible to benefit from the cheap production methods there. The integration of VCSELs on-board together with other standard components enables a modul technology.
Product overview VCSEL wavelength selection: 760nm, 763nm, 764nm, 780nm, 790nm, 795nm, 808nm, 850nm, 851nm, 852nm, 915nm, 920nm, 942nm, 945nm, 948nm, and 980nm (650nm, 660nm, 670nm, 680nm (red), 1300nm, 1310nm, 1550nm in research stadium) VCSEL laserdiodes VCSEL speed (modulation bandwidth) selection: 2.5, 3.125, 4.125, 10, 12.5 Gbps; 2,5; 3,125; 4,125; 10; 12,5 Gbp/s VCSEL Diodes VCSEL optical power selection: microwatt, milliwatt, watt-regime VCSEL laserdiode VCSEL modal behavior selection: single-mode (singlemode, single mode), multi-mode (multimode, multi mode) VCSEL laser diodes VCSEL housing / packaging selection: chip, array, TO, SMA, TOSA, LC, SC, SMA, E2000, Receptacle, pigtailed VCSEL laser diode Photodiode / PIN / PD selection: chip, array, TO, SMA, ROSA, LC, SC, SMA, Receptacle, pigtailed VCSEL photodiodes
Technical Informations Reliability First reliability testing of VCSELs was started as early as 1995 in Ulm University, from the founders of ULM photonics. These tests where conducted at room temperature and up to now the devices have shown no failures. Therefore an estimation of the reliability and an improvement of it was not possible. Since then reliability testing has been improved a lot, so that reliability measurements can be conducted today much faster, giving a fast feedback for quality control and reliability improvement. Because reliability is so important, ULM photonics has been performing excessive reliability testing since 1999 and has gathered a lot of data and made a lot of improvements in device reliability. Currently ULM photonics is able to test 496 VCSEL devices at the same time, giving more than 4 million true test hours a year. If you have any comments or request for detail product information, please mail to: info at ulm-photonics dot de. Note: If you want to mail please replace "at" by "@" and "dot" by "."
VCSEL history of Ulm
Selected publications
Press Release
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