In this work, the development of a novel ultra-short laser system is presented, building upon previous research in passive mode-locking using cross-amplitude modulation (XAM). By combining XAM with cascaded second-order nonlinearity mode-locking (CSM) the system produced a stable bright-dark two-color output with picosecond pulses and a repetition rate of 275 MHz with an average output power of 100 mW for an 808 nm pump power of 4 W. The experimental setup involved two Nd: YVO₄ lasers operating at 1064 nm and 1342 nm, where the two cavities were interconnected with a dichroic mirror allowing for a shared section where a periodically poled KTiOPO₄ (PPKTP) was introduced. In the separate sections, the independently diode-pumped laser crystals were placed. The enhanced intra-cavity intensity achieved through XAM enabled effective pulse compression via CSM. The results demonstrate the system’s ability to generate near-transform-limited pulses as short as 14 ps, offering potential for applications such as medical imaging and LIDAR.

This work demonstrates an up-conversion imaging system using silicon sensors and commercial optics. A 1550 nm laser and Nd:YVO4 laser mix in a PPKTP crystal, achieving a 61 mrad FOV and 0.96 mrad resolution.

In this work, a novel 2.7 µm source used for CO2 and H2O vapor spectroscopy using the backward propagating wave of a backward wave optical parametric oscillator (BWOPO) is demonstrated for the first time to our knowledge. The unique properties of BWOPOs eliminate the need for additional spectral narrowing or wavelength stabilization, enabling the use of a multi-longitudinal mode Q-switched pump laser centered around 1030 nm. A full characterization of the source is presented, revealing a central output at 2712 nm, showcasing a temperature tuning of −1.77 GHz/K, and achieving an output pulse energy of 2.3 µJ. Novel methods are introduced for measuring the linewidth and wavelength stability using the ambient laboratory air. These approaches demonstrate a narrow output of 43 pm and establish an upper limit of stability at 65 MHz, with no active means of stabilization. These findings underscore the potential of BWOPOs as a robust platform for future differential absorption lidar (DIAL) systems.

The first demonstration of a 2.7 µm CO2 gas sensing source exploiting a backward wave optical parametric oscillator (BWOPO). Transmission measurements of the backward wave are demonstrated through air with good agreement with simulations.

In this study, quenching dynamics in RE-doped silica glass were investigated through the measurement of excited-state lifetimes of heavily doped silica micro-hemispheres fabricated directly on the end face of a multimode fiber (MMF).

Dark optical solitons are solutions to the nonlinear Schrodinger equation in normal dispersion media with positive Kerr nonlinearity, exhibiting a discrete pi phase jump. These solitons are valuable to applications within telecommunication. Recent advancements have demonstrated the generation of two-colour bright-dark soliton pairs through cross-amplitude modulation in laser cavities, resulting in mode locking. In this study we present for the first time full field characterization of the electric field of a dark pulse. We achieved this by performing Blind Frequency Resolved Optical Gating measurements using the synchronous bright pulse as the gate pulse. The retrieved dark pulse verifies the existence of the expected p phase jump in the phase of the dark pulse, confirming theoretical predictions.

Silica fibers are highly desired due to their robustness and easy integration with existing infrastructure. Although fabrication of silica gain fibers can be performed using well-established methods e.g., Modified Chemical Vapor Deposition (MCVD), each production cycle can be time-consuming and expensive. Additive manufacturing (AM) on the other hand is an attractive way of fabrication, where reduced waste and short cycles are widely recognized. Today, AM is commonly used to make functional components and prototypes.

The pursuit of advanced fiber laser technologies has driven research toward unconventional manufacturing techniques. In this work, we present an erbium-doped fiber laser made using powder-based additive manufacturing. An Er3+/Al3+ co-doped silica glass rod was printed using laser powder deposition and then used as the core material in a fiber preform. The fiber drawn from the preform exhibited the complete, desired functionality linked to Er3+ doping. To demonstrate this, a standing wave laser cavity was formed with the feedback attained from the cleaved ends of the manufactured fiber. The high quality of the fiber is showcased through a low background loss, single-mode operation, a 9.4% laser slope efficiency, and an output of 4.5 mW, limited by the available pump power. This proof-of-concept opens up promising areas for rapid fabrication and development of high-performance fibers and fiber lasers.

Light Detection and Ranging (LIDAR) is a powerful imaging technique. By utilising a superconducting nanowire single photon detector (SNSPD) we construct a 3D scanning LIDAR system operating with eye-safe infrared laser pulses and millimeter precision. 

Light Detection and Ranging (LIDAR) is a powerful imaging technique. By utilising a superconducting nanowire single photon detector (SNSPD) we construct a 3D scanning LIDAR system operating with eye-safe infrared laser pulses and millimeter precision.