Watt-level beam combined diode laser systems in a chip-scale hybrid photonic platform.

Scaling up the power of on-chip diode lasers is of great importance for many emerging applications, such as integrated nonlinear optics, remote sensing, free space communication, infrared countermeasure, and light detection and ranging (LIDAR). In this manuscript, we introduce and demonstrate photonic integrated circuits (PIC) based beam combining methods to create power scalable, integrated direct diode laser systems. Traditional laser beam combining, including coherent beam combining (CBC) and wavelength beam combining (WBC), usually requires free space or fiber optical components, leading to bulky and complex systems.

Narrow-linewidth, tunable external cavity dual-band diode lasers through InP/GaAs-SiN hybrid integration.

We demonstrate hybridly integrated narrow-linewidth, tunable diode lasers in the InP/GaAs-SiN platform. Silicon nitride photonic integrated circuits, instead of silicon waveguides that suffer from high optical loss near 1 µm, are chosen to build a tunable external cavity for both InP and GaAs gain chips at the same time. Single frequency lasing at 1.

Loss induced coherent combining in InP-SiN hybrid platform.

Loss, as a time-reversed counterpart of gain, can also be used to control lasing in an optical system with coupled cavities. In this study, by manipulating mirror losses at different output ports of coupled Fabry-Perot cavities, an integrated coherently combined laser system is proposed and experimentally demonstrated in the InP-SiN hybrid platform. Two InP-based reflective semiconductor amplifiers are coherently combined through an adiabatic 50:50 directional coupler in silicon nitride.

Controlling the interaction between plasmon-induced transparency and guided mode resonance.

A hybrid metamaterial-waveguide (HMW) system, consisting of a plasmon-induced transparency (PIT) metamaterial layer deposited on top of a slab waveguide, is investigated at mid-infrared wavelengths. The proposed hybrid system supports three quasi-guided modes. Two of them are excited through the conventional pathway, i.

Two-dimensional photonic crystal Bragg lasers with triangular lattice for monolithic coherent beam combining.

We demonstrate an electrically pumped, single-mode, large area, edge-emitting InGaAsP/InP two-dimensional photonic crystal (PC) Bragg laser with triangular lattice. The laser operates in the single transverse and longitudinal modes with a single lobe, near-diffraction-limited far field. We compare the performance of the triangular-lattice PC Bragg laser with the rectangular-lattice PC Bragg laser fabricated from the same wafer and find that their performances are comparable.

Hybrid distributed Raman amplification combining random fiber laser based 2nd-order and low-noise LD based 1st-order pumping.

A configuration of hybrid distributed Raman amplification (H-DRA), that is formed by incorporating a random fiber laser (RFL) based 2nd-order pump and a low-noise laser-diode (LD) based 1st-order pump, is proposed in this paper. In comparison to conventional bi-directional 1st-order DRA, the effective noise figure (ENF) is found to be lower by amount of 0 to 4 dB due to the RFL-based 2nd-order pump, depending on the on-off gain, while the low-noise 1st-order Raman pump is used for compensating the worsened signal-to-noise ratio (SNR) in the vicinity towards the far end of the fiber and avoiding the potential nonlinear impact induced by excess injection of pump power and suppressing the pump-signal relative intensity noise (RIN) transfer. As a result, the gain distribution can be optimized along ultra-long fiber link, due to combination of the 2nd-order RFL and low-noise 1st-order pumping, making the transmission distance be extended significantly.

Distributed Raman amplification using ultra-long fiber laser with a ring cavity: characteristics and sensing application.

Distributed Raman amplification (DRA) based on ultra-long fiber laser (UL-FL) pumping with a ring cavity is promising for repeaterless transmission and sensing. In this work, the characteristics (including gain, nonlinear impairment and noise figure) for forward and backward pumping of the ring-cavity based DRA scheme are fully investigated. Furthermore, as a typical application of the proposed configuration, ultra-long-distance distributed sensing with Brillouin optical time-domain analysis (BOTDA) over 142.