The application of 3D holograms is far-reaching, especially in the field of medical technology. It is expected that real-time dynamic holograms can shorten surgical time and provide better surgical results. Dynamic three-dimensional holograms may replace current two-dimensional imaging, such as magnetic resonance imaging, allowing surgeons to have a more comprehensive and real-time understanding of the patient’s internal system, thereby reducing the invasiveness of surgery and unexpected situations during the surgical process.
The widespread adoption of 3D holograms requires a new type of micro optical system that can be integrated on chips with minimal power consumption, move beams into free space, control beam shape, and have adjustable wavefronts. Although existing technology can answer these questions, it has been difficult to combine them into a system so far.
TMOS is the center of excellence for metasurface optical systems at the Australian Research Council. The researchers at the center used metasurface optics to combine vertical nanowires with micro ring lasers made of semiconductor nanostructures, bringing this technology closer to reality.
Vertical nanowires themselves have special directionality and can effectively form laser beams, but their configuration can lead to significant photon leakage during the laser process. The position where the photon reflecting mirror is located is also where the nanowire is connected to the substrate, making the nanowire an inefficient laser.
On the other hand, in micro ring lasers, most photons move parallel to the substrate, reducing photon leakage and achieving higher laser efficiency. However, controlling the direction and shape of the beam is very difficult.
TMOS researchers have combined InP micro ring laser cavities with vertical InP nanowire antennas for the first time in the world. The antenna is located at the center of the cavity, guiding photons into a free space with a specific beam shape. This is the development required for 3D holograms. Using selective region epitaxy as the light source and antenna to simultaneously grow microrings and nanowire cavities.
The size of the device is less than 5 μ m。 Ultimately, a single holographic pixel can be formed. The effectiveness of this coupling has been proved in the laboratory, and the details are published in the journal Laser and photonics Review.
Wei Wen Wong, the lead author of the study, said: This is a path towards low-power, tunable emission on chip micro lasers. This new development eliminates the key obstacle to achieving 3D holograms. We hope that this novel device can one day be integrated into a small enough and affordable device, allowing medical professionals to put it in their pockets when traveling to remote areas, allowing them to project full color dynamic holograms on the on-site operating table
The development of dynamic holograms is one of the flagship projects of our center. Teams from five participating universities are working together to make this goal a reality. Our next step in research is to create a pixel array where the wavefront and beam shape can be individually controlled and dynamically adjusted.