Skip to Content

Diamond Laser Group

Research in Diamond Nonlinear Optics

Research in the Diamond Laser Group at Macquarie University seeks to exploit the extraordinary optical and physical properties of diamond and related materials. Diamond’s high gain for stimulated scattering (Raman and Brillouin), outstanding thermal conductivity and broad optical transmission, makes it interesting for exploring new regimes of optical performance and is promising for realising miniature devices of high power and wide frequency range.

Diamond Lasers

Stimulated scattering in diamond enables laser action at almost any wavelength across its extremely large transparency range. Coupled with diamond's high thermal conductivity and particular nonlinear properties, lasers across the spectrum are possible with high power and high coherence. We are investigating devices capable of high spectral and spatial power density to address applications in environmental sensing, health, industry and security. We have recently discovered Brillouin laser action in diamond, which provides an additional pathway to extend enhance coherence and explore frequency synthesis in the microwave and mmWave domains. It possesses a higher gain coefficient than most other materials, which along with its extremely high speed of sound, provides a set of unique advantages. On of our major current topics of emphasis is in exploring diamond lasers for low-noise, narrow-linewidth operation to address challenges in areas such as space adaptive optics and quantum science.

Surface Structuring of Diamond

Many of the same properties that make diamond interesting for applications in photonics, electronics, and micro-mechanics create severe difficulties in shaping the material into the desired form. Our research explores new methods of manipulating diamond surfaces by using a recently-discovered 2-photon technique of carbon atom removal. This optical technique, which is rather peculiar amongst other optical material interactions, is highly promising as a novel technique for structuring and functionalizing diamond surfaces. As an example, we have demonstrated that it is possible to optically and controllably remove single atomic layers (or fractions thereof). Our research on this topic involves investigations into understanding the underlying physics behind carbon ejection and its potential as new tool for diamond processing. Applications for the process include the fabrication of diamond-based quantum devices and diamond surface electronics.

Power Scaling Diamond Lasers

Quasi-cw operation has enabled investigation of cw conversion at greatly elevated powers. Preliminary experiments have demonstrated 1.2 kW TEM00 beam power, which is already approaching the levels of conventional high power laser such as fibre and disk lasers. The on-time burst duration of 0.1 ms is long compared to the time needed to establish steady-state temperature gradients in the diamond crystal and thus these results are also indicative of what might be achieved for true-cw operation. Improved efficiency and further power scaling is anticipated with cavity optimization and increased pump power. We exploring methods for pumping diamond using low coherence sources such as laser diodes or via beam combination.

On-chip Diamond Waveguide Devices

Waveguides have the potential for efficient, low threshold and compact frequency converters that can be integrated into on-chip devices. We are investigating techniques to fabricate novel waveguide structures in these materials using a variety of laser, plasma and mechanical polishing techniques. Our research currently focusses on developing low threshold devices with wide wavelength range which have exciting prospects for applications in quantum computing, optofluidics, biophotonics and sensing.