| 1. |
- Gustavsson, Johan, 1974, et al.
(författare)
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High-speed 850-nm VCSELs for 40 Gb/s transmission
- 2010
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- We have explored the possibility to extend the data transmission rate for standard 850-nm GaAs-based VCSELs beyond the 10 Gbit/s limit of today's commercially available directly-modulated devices. By sophisticated tailoring of the design for high-speed performance we demonstrate that 10 Gb/s is far from the upper limit. For example, the thermal conductivity of the bottom mirror is improved by the use of binary compounds, and the electrical parasitics are kept at a minimum by incorporating a large diameter double layered oxide aperture in the design. We also show that the intrinsic high speed performance is significantly improved by replacing the traditional GaAs QWs with strained InGaAs QWs in the active region. The best overall performance is achieved for a device with a 9 μm diameter oxide aperture, having in a threshold current of 0.6 mA, a maximum output power of 9 mW, a thermal resistance of 1.9 °C/mW, and a differential resistance of 80 Ω. The measured 3dB bandwidth exceeds 20 GHz, and we experimentally demonstrate that the device is capable of error-free transmission (BER
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| 2. |
- Larsson, Anders, 1957, et al.
(författare)
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High speed VCSELs for optical interconnects
- 2012
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Ingår i: Conference Proceedings - International Conference on Indium Phosphide and Related Materials. - 1092-8669. - 9781467317252 ; , s. 269-272
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Konferensbidrag (refereegranskat)abstract
- This paper presents an overview of our recent work on high speed, oxide confined, 850 nm vertical cavity surface emitting lasers (VCSELs). With proper active region and cavity designs, and techniques for reducing capacitance and thermal impedance, we have reached a modulation bandwidth of 23 GHz and demonstrated 40 Gbps transmission. Using an integrated mode filter for reducing the spectral width we have extended the reach on multimode fiber at 25 Gbps from 100 to 500 m. Improved link capacity was also demonstrated using a more spectrally efficient multi-level modulation format (4-PAM). Finally, a MEMS-technology for wafer scale integration of tunable high speed VCSELs was developed, enabling a tuning range of 24 nm, a 6 GHz modulation bandwidth, and 5 Gbps transmission.
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| 3. |
- Szczerba, Krzysztof, 1985, et al.
(författare)
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30 Gbps 4-PAM transmission over 200m of MMF using an 850 nm VCSEL
- 2011
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Ingår i: Optics Express. - 1094-4087 .- 1094-4087. ; 19:26, s. B203-B208
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Tidskriftsartikel (refereegranskat)abstract
- We present high speed real time, error free 4-PAMtransmissionfor short range optical links based on a VCSEL operating at 850 nm, a multimode fibre and a simple intensity detector. Transmission speeds of 25 Gbps and 30 Gbps are demonstrated, and the maximum fibre reaches were 300 m and 200 m, respectively. The 4-PAM is also compared with OOK transmission at 25 Gbps, and we find that at this bit rate 4-PAM increases the error free transmission distance in the multimode fibre by 100 m, compared to OOK.
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| 4. |
- Szczerba, Krzysztof, 1985, et al.
(författare)
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30 Gbps 4-PAM transmission over 200m of MMF using an 850 nm VCSEL
- 2011
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Ingår i: European Conference and Exposition on Optical Communications, ECOC. - 2162-2701. - 9781557529312 ; , s. 1-3
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Konferensbidrag (refereegranskat)abstract
- Real time, error free 4-PAM transmission at 25 Gbps and 30 Gbps over 300 m and200m of multimode fiber, respectively, using a VCSEL operating at the wavelength of 850 nm.
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| 5. |
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| 6. |
- Szczerba, Krzysztof, 1985, et al.
(författare)
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4-PAM for high-speed short-range optical communications
- 2012
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Ingår i: Journal of Optical Communications and Networking. - 1943-0620 .- 1943-0639. ; 4:11, s. 885-894
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we compare 4-pulse amplitudemodulation and on–off keying modulation formats at highspeed for short-range optical communication systems. Thetransmission system comprised a directly modulated verticalcavitysurface-emitting laser operating at a wavelength of850 nm, an OM3Å multimode fiber link, and a photodetectordetecting the intensity at the receiver end. The modulationformats were compared both at the same bit-rate and at thesame symbol rate. The maximum bit-rate used was 25 Gbps.Propagation distances up to 600 m were investigated at12.5 Gbps. All measurements were done in real time andwithout any equalization.
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