Abstract

In recent years, Terahertz (THz) quantum cascade lasers (QCLs) have undergone a fast development, showing high power, ultra-broadband gain and quantum-limited linewidth. For many applications, THz QCLs need to operate in continuous-wave (CW), with a tight control of the emission spectrum and highly collimated beam profiles. These requirements are usually addressed by exploiting distributed feedback (DFB), photonic crystals or micro-cavity architectures, which can allow tailoring either the laser beam divergence or the emission frequency, and eventually both of them simultaneously, as in the case of third-order DFBs. Here we report on an original design in which a wire DFB THz QCL, engineered with a lateral sinusoidal corrugation providing feedback and frequency control, and an array of surface hole provides light outcoupling. This new photonic structure has led to the achievement of low-divergence beams (10°), single-mode emission, high slope efficiencies (250 mW/A), and stable CW operation.

Highlights

  • Terahertz (THz) quantum cascade lasers (QCLs) have undergone rapid development since their demonstration, showing high power, broad-tunability, quantum-limited linewidth, and ultra-broadband gain

  • Microcavities[4], photonic crystals[5,6], and both pseudo-random[7,8] and random[9] photonic structures, can manipulate and confine light in small volumes, and at targeted frequencies. This has further expanded the functionality of the THz QCL, allowing operation at a single emission frequency[7] or over a broad (0.5 THz) frequency bandwidth, or with designed directional beam patterns[8]

  • We demonstrate double-metal waveguided distributed feedback (DFB) THz quantum cascade wire lasers, exploiting an innovative approach in which feedback is provided by a lateral sinusoidal ridge corrugation, while light extraction is separately controlled by a hole array in the top metallization

Read more

Summary

Introduction

Terahertz (THz) quantum cascade lasers (QCLs) have undergone rapid development since their demonstration, showing high power, broad-tunability, quantum-limited linewidth, and ultra-broadband gain. We demonstrate double-metal waveguided DFB THz quantum cascade wire lasers, exploiting an innovative approach in which feedback is provided by a lateral sinusoidal ridge corrugation, while light extraction is separately controlled by a hole array in the top metallization.

Results
Conclusion

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.