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Barve različnih polprevodniških izvorov in občutljivost oči. Valovna dolžina (nm). Band structure: direct vs. indirect Eg. Elektronska stanja v heterostrukturah. Koncentracija (omejevanje) elektronov in svetlobe v tanki plasti. Kvantne jame, enojne in večkratne.
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Barve različnih polprevodniških izvorov in občutljivost oči • Valovna dolžina (nm)
Elektronska stanja v heterostrukturah Koncentracija (omejevanje) elektronov in svetlobe v tanki plasti Kvantne jame, enojne in večkratne
LED: kako do svetlobe iz polprevodnika? Kako • Geometrija je pomembna zaradi loma na meji polprevodnika
OCLARO 10 W laserska dioda z optičnim vlaknom - karakteristike
“LASERS” ….. Example: CD Diode Lasers output in the near-infrared ≈ 5 – 50mW output actual laser chip from a CD player Dr. Mike Nofziger 2010
VCSELs high performance and low cost advantages. 1. The structure can be integrated in two-dimensional array configuration. 2. Low threshold currents enable high-density arrays. 3. Surface-normal emission and nearly identical to the photo detector geometry -> easy alignment and packaging. 4. Circular and low divergence output beams eliminate the need for corrective optics.
5. Passive versus active fiber alignment, combined with high fiber-coupling efficiency. 6. Low-cost potential because the devices are completed and tested at the wafer level. 7. Lower temperature-sensitivity compared to edge-emitting laser diodes. 8. High transmission speed with low power consumption.
“LASERS” ….. Example: High-Power Diodes • Stacks of linear arrays of diode lasers • 100’s to kilowatts of power • near infrared wavelengths • used for materials processing Dr. Mike Nofziger 2010
Kvantna kaskada – zaporedje prehodov med kvantnimi jamami
Quantum cascade lasers Banddiagram Layer sequence Emission spectrumat room temperature Light-andVolt-currentcharacteristics
The European x-ray free electron laser (European XFEL) an X-ray research laser facility currently under construction planned to be operational by the end of 2017. 12 participating countries (Denmark, France, Germany, Greece, Hungary, Italy, Poland, Russia, Slovakia, Spain, Sweden and Switzerland) Electrons will be accelerated to an energy of up to 17.5 GeV by a 2.1 km long superconductinglinear accelerator. Total length 3.4 km. Wavelength 0.05 to 6 nm