skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: Measured optical losses of Sc doped AlN waveguides
Although Sc doped AlN (ScAlN) has been used extensively in micro-electro-mechanical systems (MEMS) devices and more recently in optical devices, there have not been thorough studies of its intrinsic optical losses. Here we explore the optical losses of the Sc0.30Al0.70N waveguide system by observing racetrack resonator waveguide quality factors. Using a partial physical etch, we fabricate waveguides and extract propagation losses as low as 1.6 ± 0.3 dB/cm at wavelengths around 1550 nm, mostly dominated by intrinsic material absorption from the Sc0.30Al0.70N thin film layer. The highest quality factor of the resonators was greater than 87,000. The propagation loss value is lower than any value previously published and shows that this material can be broadly used in optical modulators without significant loss.  more » « less
Award ID(s):
1905834
PAR ID:
10488461
Author(s) / Creator(s):
; ; ; ; ;
Publisher / Repository:
Optical Society of America
Date Published:
Journal Name:
Optics Express
Volume:
32
Issue:
4
ISSN:
1094-4087; OPEXFF
Format(s):
Medium: X Size: Article No. 5252
Size(s):
Article No. 5252
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; ; (, APL Materials)
    Silicon photonics has enabled large-scale production of integrated optical devices for a vast array of applications. However, extending its use to nonlinear devices is difficult since silicon does not exhibit an intrinsic second-order nonlinearity. While heterogeneous integration of strongly nonlinear materials is possible, it often requires additional procedures since these materials cannot be directly grown on silicon. On the other hand, CMOS-compatible materials often suffer from weaker nonlinearities, compromising efficiency. A promising alternative to current material platforms is scandium-doped aluminum nitride (Al1−xScxN), which maintains the CMOS compatibility of aluminum nitride (AlN) and has been used in electrical devices for its enhanced piezoelectricity. Here, we observe enhancement in optical second-order susceptibility (χ(2)) in CMOS-compatible Al1−xScxN thin films with varying Sc concentrations. For Al0.64Sc0.36N, the χ(2) component d33 is enhanced to 62.3 ± 5.6 pm/V, which is 12 times stronger than intrinsic AlN and twice as strong as lithium niobate. Increasing the Sc concentration enhances both χ(2) components, but loss increases with a higher Sc concentration as well, with Al0.64Sc0.36N exhibiting 17.2 dB/cm propagation loss at 1550 nm and Al0.80Sc0.20N exhibiting 8.2 dB/cm at 1550 nm. Since other material properties of this alloy are also affected by Sc, tuning the Sc concentration can balance strong nonlinearity, loss, and other factors depending on the needs of specific applications. As such, Al1−xScxN could facilitate low cost development of nonlinear integrated photonic devices. 
    more » « less
  2. ; ; ; ; ; ; ; (, Proceedings of the SPIE)
    Chemicals are best recognized by their unique wavelength specific optical absorption signatures in the molecular fingerprint region from λ=3-15μm. In recent years, photonic devices on chips are increasingly being used for chemical and biological sensing. Silicon has been the material of choice of the photonics industry over the last decade due to its easy integration with silicon electronics as well as its optical transparency in the near-infrared telecom wavelengths. Silicon is optically transparent from 1.1 μm to 8 μm with research from several groups in the mid-IR. However, intrinsic material losses in silicon exceed 2dB/cm after λ~7μm (~0.25dB/cm at λ=6μm). In addition to the waveguiding core, an appropriate transparent cladding is also required. Available core-cladding choices such as Ge-GaAs, GaAs-AlGaAs, InGaAs-InP would need suspended membrane photonic crystal waveguide geometries. However, since the most efficient QCLs demonstrated are in the InP platform, the choice of InGaAs-InP eliminates need for wafer bonding versus other choices. The InGaAs-InP material platform can also potentially cover the entire molecular fingerprint region from λ=3-15μm. At long wavelengths, in monolithic architectures integrating lasers, detectors and passive sensor photonic components without wafer bonding, compact passive photonic integrated circuit (PIC) components are desirable to reduce expensive epi material loss in passive PIC etched areas. In this paper, we consider miniaturization of waveguide bends and polarization rotators. We experimentally demonstrate suspended membrane subwavelength waveguide bends with compact sub-50μm bend radius and compact sub-300μm long polarization rotators in the InGaAs/InP material system. Measurements are centered at λ=6.15μm for sensing ammonia 
    more » « less
  3. ; ; (, Optics Express)
    Photonic integrated circuits based on ultralow loss silicon nitride waveguides have shown significant promise for realizing high-performance optical systems in a compact and scalable form factor. For the first time, we have developed a Fabry-Perot Bragg grating nanoresonator based on silicon nitride on silicon dioxide platform with an ultra-high intrinsic quality factor of 19.3 million. By combining the introduction of tapered grating between cavity and periodic Bragg grating, increasing the width of cavity to multi-mode region and optimized annealing strategy for Si3N4film, the propagation loss is reduced to around 0.014 dB/cm. Fabry-Perot Bragg grating nanoresonator can be easily implemented in a simple straight waveguide occupying a minimal amount of space. Therefore, it is a key component to build a high performance photonic integrated circuit for many applications. 
    more » « less
  4. ; ; ; ; ; (, Nanophotonics)
    Abstract Commercial production of integrated photonic devices is limited by scalability of desirable material platforms. We explore a relatively new photonic material, AlScN, for its use in electro-optic phase shifting and modulation. Its CMOS-compatibility could facilitate large-scale production of integrated photonic modulators, and it exhibits an enhanced second-order optical nonlinearity compared to intrinsic AlN, indicating the possibility for efficient modulation. Here, we measure the electro-optic effect in Al0.80Sc0.20N-based phase shifters. We utilized the TM0 mode, allowing use of ther33electro-optic coefficient, and demonstratedVπLaround 750 V cm. Since the electro-optic response is smaller than expected, we discuss potential causes for the reduced response and future outlook for AlScN-based photonics. 
    more » « less
  5. ; ; ; ; ; ; ; (, Nanomaterials)
    Polar van der Waals (vdW) crystals, composed of atomic layers held together by vdW forces, can host phonon polaritons—quasiparticles arising from the interaction between photons in free-space light and lattice vibrations in polar materials. These crystals offer advantages such as easy fabrication, low Ohmic loss, and optical confinement. Recently, hexagonal boron nitride (hBN), known for having hyperbolicity in the mid-infrared range, has been used to explore multiple modes with high optical confinement. This opens possibilities for practical polaritonic nanodevices with subdiffractional resolution. However, polariton waves still face exposure to the surrounding environment, leading to significant energy losses. In this work, we propose a simple approach to inducing a hyperbolic phonon polariton (HPhP) waveguide in hBN by incorporating a low dielectric medium, ZrS2. The low dielectric medium serves a dual purpose—it acts as a pathway for polariton propagation, while inducing high optical confinement. We establish the criteria for the HPhP waveguide in vdW heterostructures with various thicknesses of ZrS2 through scattering-type scanning near-field optical microscopy (s-SNOM) and by conducting numerical electromagnetic simulations. Our work presents a feasible and straightforward method for developing practical nanophotonic devices with low optical loss and high confinement, with potential applications such as energy transfer, nano-optical integrated circuits, light trapping, etc. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email