CW and mode-locked integrated extended cavity lasers fabricated using impurity free vacancy disordering

Bryce, A. C., Camacho, F., Cusumano, P. and Marsh, J. H. (1997) CW and mode-locked integrated extended cavity lasers fabricated using impurity free vacancy disordering. IEEE Journal of Selected Topics in Quantum Electronics, 3(3), pp. 885-892. (doi: 10.1109/2944.640642)

Abstract

A phosphorus-doped silica (P:SiO/sub 2/) cap containing 5 wt% P has been demonstrated to inhibit the bandgap shifts of p-i-n and n-i-p GaAs-AlGaAs quantum-well laser structures during rapid thermal processing. Bandgap shift differences as large as 100 meV have been observed between samples capped with SiO/sub 2/ and with P:SiO/sub 2/. The technique has been used to fabricate GaAs-AlGaAs ridge lasers with integrated transparent waveguides. With a selective differential blue-shift of 30 nm in the absorption edge, devices with 400 /spl mu/m/2.73-mm-long active/passive sections exhibited an average threshold current of 9 mA in continuous-wave (CW) operation, only 2.2 mA higher than that of discrete lasers of the same active length and from the same chip. Extended cavity mode-locked lasers were also investigated and compared to all active devices. For the extended cavity device, the threshold current is a factor of 3-5 lower, the pulsewidth is reduced from 10.3 to 3.5 ps and there is a decrease in the free-running jitter level from 15 ps (measurement bandwidth 10 kHz-10 MHz) to 6 ps. In addition, the extended cavity lasers do not exhibit any self-pulsing modulation of the mode-locked pulse train, unlike the all-active lasers, and the optical spectra indicate that the pulses are more linearly chirped.

• Item Type: Articles
• Additional Information: This work was supported by the UK Ministry of Defence and EPSRC under Grant no. GR/K45968. The work of P. Cusumano was supported by the European Community, within the frame of the Human Capital and Mobility Program.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Marsh, Professor John
• Authors: Bryce, A. C., Camacho, F., Cusumano, P., and Marsh, J. H.
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Journal Name: IEEE Journal of Selected Topics in Quantum Electronics
• Publisher: Institute of Electrical and Electronics Engineers
• ISSN: 1077-260X
• ISSN (Online): 1558-4542