English

Researchers have manufactured chip based optical resonators that can operate in the ultraviolet (UV) and visible light regions of the spectrum

109
2023-10-06 11:44:19
See translation

 

Figure: Researchers have created a chip based ring resonator that operates in the ultraviolet and visible light ranges and exhibits record low UV loss. The resonator (small circle in the middle) is displayed as blue light.

Researchers have created chip based photonic resonators that can operate in the ultraviolet (UV) and visible regions of the spectrum and exhibit record low UV loss. The new resonator lays the foundation for increasing the size, complexity, and fidelity of UV photonic integrated circuit (PIC) design, which can enable new microchip based devices for applications such as spectral sensing, underwater communication, and quantum information processing.

Compared to more mature fields such as telecommunications photonics and visible photonics, the exploration of ultraviolet photonics is relatively limited, despite the need for ultraviolet wavelengths to access certain atomic transitions and excite certain fluorescent molecules used for biochemical sensing in atomic/ion based quantum calculations, "said Cheng He, a research team member at Yale University. Our work has laid a solid foundation for constructing photonic circuits that operate at ultraviolet wavelengths.

In Optics Express, researchers described optical microresonators based on alumina and how they achieved unprecedented low losses at UV wavelengths by combining the correct materials with optimized design and manufacturing.

Our work indicates that UV PICs have reached a critical point where the optical loss of waveguides is no longer more severe than that of visible light, "said Hong Tang, the head of the research team. This means that all interesting PIC structures developed for visible and telecommunications wavelengths, such as frequency combs and injection locking, can also be applied to ultraviolet wavelengths.

Reduce light loss
The micro resonator is made of high-quality aluminum oxide film, which was prepared by Integras using a highly scalable atomic layer deposition (ALD) process. The large bandgap (~8eV) of alumina makes it transparent to ultraviolet photons with much lower energy (~4eV) than the bandgap. Therefore, this material does not absorb ultraviolet rays.

The previous record was completed using aluminum nitride, with a bandgap of~6eV, "he said. Compared to single crystal aluminum nitride, amorphous ALD alumina has fewer defects and is less difficult to manufacture, which helps us achieve lower losses.

In order to manufacture micro resonators, researchers etched aluminum oxide to create what is commonly known as a ridge waveguide, in which a plate with a strip at the top forms a structure that restricts light. The deeper the spine, the stronger the constraint, but the greater the scattering loss. They use simulation to find the appropriate etching depth to achieve the required light constraints while minimizing scattering losses.

Manufacturing ring resonators
The researchers applied the knowledge they learned from waveguides to manufacturing circular resonators with a radius of 400 microns. They found that in a 400 nm thick alumina film, when the etching depth exceeds 80 nm, the radiation loss at 488.5 nm can be suppressed to less than 0.06 dB/cm, and the radiation loss at 390 nm can be suppressed to less than 0.001 dB/cm.

After manufacturing a ring resonator based on these calculations, researchers determined the Q-factor by measuring the width of the resonant peak, while scanning the optical frequency injected into the resonator. They found that the Q-factor reached a record high of 1.5 e6 at 390 nanometers (in the ultraviolet part of the spectrum), and 1.9 e6 at 488.5 nanometers (in the wavelength of visible blue light). The higher the q factor, the less optical loss.

He said, "Compared to PICs of visible light or telecommunication wavelengths, UV PICs may have advantages in communication due to their larger bandwidth or under conditions where other wavelengths are absorbed (such as underwater)." In addition, the atomic layer deposition process used for manufacturing alumina is compatible with CMOS, paving the way for the integration of CMOS and amorphous alumina based photonics.

Researchers are currently working on developing ring resonators based on alumina, which can be tuned to different wavelengths. This can be used to achieve precise wavelength control or to create modulators by using two mutually interfering resonators. They also want to develop an integrated PIC UV light source to form a complete PIC based UV system.

Source: Laser Network

Related Recommendations
  • The influence of laser beam drift on SLM thin-walled TC11 specimens at high scanning speed

    AbstractDue to the width of the laser melt pool and the sintering effect on the surrounding powder, the experimental size of the selective laser melting (SLM) sample will be larger than the design size, which will greatly affect the dimensional accuracy and surface quality of the thin-walled sample. In order to obtain SLM thin-walled TC11 specimens with precise dimensions, an orthogonal experiment...

    02-24
    See translation
  • Stratasys announces Q3 2024 financial report, with a net loss of $26.6 million

    Stratasys (Nasdaq: SSYS) has announced its earnings for the third quarter of 2024, indicating a bright future for the company. The company is increasing profits and gross margins by cutting costs and focusing more on rapidly growing industries such as aerospace, automotive, defense, medical equipment, and dentistry. CEO Yoav Zeif shared that the new F3300 3D printer has performed well in the marke...

    2024-11-15
    See translation
  • Yawei Group and Zhonggang Metal signed a complete set of sheet metal laser processing equipment to assist in the development of curtain wall materials industry

    Recently, Yawei Group signed a complete set of sheet metal laser processing equipment with Hubei Zhonggang Metal Xianning Second Production Base, adding bricks and tiles to the takeoff of Zhonggang Metal Business. After full production, the annual production of various aluminum metal plates will exceed 6 million square meters, and Zhonggang Metal will usher in another leap forward development!Zhon...

    2023-11-03
    See translation
  • The technological iteration route of automotive millimeter wave radar chips

    The rapid development of intelligent cars and autonomous driving technology has made millimeter wave radar inconspicuous, and the widespread application of millimeter wave radar has driven the technological evolution of MMIC.From the expensive gallium arsenide (GaAs) process in the early days to the mainstream CMOS and SiGe processes today, and then to the future promising FD-SOI process, the cont...

    2024-12-07
    See translation
  • Coherent launches 12 kW sheet metal laser cutting processing head

    Recently, Coherent, an industrial laser technology giant, announced the launch of a new 2D laser cutting head - CUT12, which combines excellent performance, high versatility, and profound value for the global flat cutting market. Image source: CoherentThe CUT12 sheet metal laser cutting processing head is perfectly compatible with fiber lasers in the power range of 4 kW-12 kW (continuous wave),...

    2024-10-29
    See translation