Mode-locked ultrashort pulses from an 8 $\mu$m wavelength semiconductor laser

Abstract

Quantum cascade lasers (QCL) have revolutionized the generation of mid-infrared light. Yet, the ultrafast carrier transport in mid-infrared QCLs has so far constituted a seemingly insurmountable obstacle for the formation of ultrashort light pulses. Here, we demonstrate that careful quantum design of the gain medium and control over the intermode beat synchronization enable transform-limited picosecond pulses from QCL frequency combs. Both an interferometric radio-frequency technique and second-order autocorrelation shed light on the pulse dynamics and confirm that mode-locked operation is achieved from threshold to rollover current. Being electrically pumped and compact, mode-locked QCLs pave the way towards monolithically integrated non-linear photonics in the molecular fingerprint region beyond 6 $\mu$m wavelength.

References in corpus (2)

• Gain dynamics in a heterogeneous terahertz quantum cascade laser
• Pulses from a mid-infrared quantum cascade laser frequency comb using an external compressor

Cited by in corpus (6)

• Dissipative Kerr solitons in semiconductor ring lasers
• Femtosecond pulses from a mid-infrared quantum cascade laser
• Unifying frequency combs in active and passive cavities: Temporal solitons in externally-driven ring lasers
• Mid-infrared quantum cascade laser frequency combs with a microstrip-like line waveguide geometry
• Engineering the spectral bandwidth of quantum cascade laser frequency combs
• Efficient computation of coherent multimode instabilities in lasers using a spectral approach