Agile Spectral Multiplication of Narrow-Band Comb using Integrated InP Multi-wavelength Laser

Chip-scale frequency comb sources, due to their reduced footprint, low cost, and energy efficiency, have revolutionized, among others, the fields of communications, metrology, and sensing. The generated frequency combs, however, suffer from a trade-off between bandwidth and controllability of its envelope and tone spacing. Here, we present an approach to overcome this trade-off by enabling agile spectral multiplication of a narrowband comb. By leveraging the nonlinear dynamics of a single InP distributed Bragg reflector (DBR) laser under modulated optical injection, we can achieve spectral multiplication of an injected narrowband comb at frequency offsets of up to 1.3 THz. We also demonstrate nanosecond-scale feedback-controlled tuning speed of the laser emission by a monolithically integrated feedback cavity. Lastly, we propose a technique to phase lock the multiplied combs through cascaded phase locking and show that our approach is scalable and potentially covering a range of several THz with a suitable laser design, compatible with generic foundry platforms.