1.3-Μm InAsP modulation-doped MQW lasers

摘要

The effect of both n-type and p-type modulation doping onnmultiple-quantum-well (MQW) laser performances was studied usingngas-source molecular beam epitaxy (MBE) with the object of the furthernimprovement of long-wavelength strained MQW lasers. The obtainednthreshold current density was as low as 250 A/cm2 forn1200-Μm-long devices in n-type modulation-doped MQW (MD-MQW) lasers.nA very low CW threshold current of 0.9 mA was obtained in 1.3-ΜmnInAsP n-type MD-MQW lasers at room temperature, which is the lowest evernreported for long-wavelength lasers using n-type modulation doping, andnthe lowest value for lasers grown by all kinds of MBE in thenlong-wavelength region. Both a reduction of the threshold current andnthe carrier lifetime in n-type MD MQW lasers caused the reduction of thenturn-on delay time by about 30%. The 1.3-Μm InAsP strained MQW lasersnusing n-type modulation doping with very low power consumption and smallnturn-on delay time are very attractive for laser array applications innhigh-density parallel optical interconnection systems. On the othernhand, the differential gain was confirmed to increase by a factor ofn1.34 for p-type MD MQW lasers (NA=5×1018 cmn-3) as compared with undoped MQW lasers, and the turn-onndelay time was reduced by about 20% as compared with undoped MQW lasers.nThese results indicate that p-type modulation doping is suitable fornhigh-speed lasers