Carrier relaxation enhanced by optical confinement in InP/InGaAs phase-shifted distributed Bragg reflector

Ultrafast carrier dynamics in an InP/InGaAs phase-shifted distributed Bragg reflector is studied by means of transient reflectance measurements. Transient reflectance of the phase-shifted Bragg reflector shows ultrafast relaxation of relaxation time constant of /spl ap/200 fs due to carrier-carrier scattering. Such ultrafast relaxation is not observed in a bulk InGaAs. Carrier-carrier scattering is thus enhanced in the phase-shifted Bragg reflector by optical confinement.