Publication IEICE TRANSACTIONS on ElectronicsVol.E84-CNo.3pp.331-338 Publication Date: 2001/03/01 Online ISSN: DOI: Print ISSN: 0916-8516 Type of Manuscript: Special Section PAPER (Special Issue on Optical Interconnects/Optical Signal Processing) Category: Device Keyword: VCSEL, GaAs (311)B, polarization, array,
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Summary: We have demonstrated a dynamically stable polarization operation of GaInAs/GaAs vertical-cavity surface-emitting laser (VCSEL) array grown on a GaAs (311)B substrate. A fabricated 3 3 VCSEL array consists of devices with an oxide aperture of 3.4 µm 3.4 µm. The threshold current was 0.61 0.05 mA and the threshold voltage was 1.79 0.03 V. All of the devices exhibited single-transverse mode operation with an injection current up to three times the threshold. The side-mode suppression ratio (SMSR) is larger than 30 dB. The array also exhibited stable-polarization operation with an orthogonal polarization suppression ratio (OPSR) of over 25 dB. We measured the time-resolved OPSR under square-wave direct modulation. It was found that the orthogonal non-lasing mode was suppressed even at the first peak of relaxation oscillation with OPSR > 17 dB. In an experiment of 5 Gb/s non-return-to-zero (NRZ) pseudo-random bit sequence (PRBS) modulation, the OPSR was maintained being greater than 27 dB. These observed stable and single polarization characteristics were originated from the anisotropic optical gain of strained GaInAs/GaAs quantum wells formed on (311)B substrate. We also carried out an intensity noise measurement under single-transverse and stable polarization operation for the first time. The relative intensity noise (RIN) of -140 dB/Hz was obtained. In addition, we achieved 2.5 Gb/s data transmission through a 100 m multi-mode fiber. No error floor was observed at -20 dBm of received power level. The minimum received power is determined by the thermal noise.