An official website of the United States government
Silicon carbide (SiC) has great potential for optomechanical applications due to its outstanding optical and mechanical properties. However, challenges associated with SiC nanofabrication have constrained its adoption in optomechanical devices, as embodied by the considerable optical loss or lack of integrated optical access in existing mechanical resonators. In this work, we overcome such challenges and demonstrate a low-loss, ultracompact optomechanical resonator in an integrated 4H-SiC-on-insulator (4H-SiCOI) photonic platform for the first time, to our knowledge. Based on a suspended 4.3-μm-radius microdisk, the SiC optomechanical resonator features low optical loss (<1 dB/cm), a high mechanical frequencyfmof 0.95×109 Hz, a mechanical quality factorQmof 1.92×104, and a footprint of <1×10−5 mm2. The correspondingfm·Qmproduct is estimated to be 1.82×1013 Hz, which is among the highest reported values of optomechanical cavities tested in ambient environment at room temperature. In addition, the strong optomechanical coupling in the SiC microdisk enables coherent regenerative optomechanical oscillations at a threshold optical dropped power of 14 μW, which also supports efficient harmonic generation at increased power levels. With such competitive performance, we envision a range of chip-scale optomechanical applications to be enabled by the low-loss 4H-SiCOI platform.
more »
« less
Twenty-nine million intrinsic Q -factor monolithic microresonators on thin-film lithium niobate
The recent emergence of thin-film lithium niobate (TFLN) has extended the landscape of integrated photonics. This has been enabled by the commercialization of TFLN wafers and advanced nanofabrication of TFLN such as high-quality dry etching. However, fabrication imperfections still limit the propagation loss to a few dB/m, restricting the impact of this platform. Here, we demonstrate TFLN microresonators with a record-high intrinsic quality (Q) factor of twenty-nine million, corresponding to an ultra-low propagation loss of 1.3 dB/m. We present spectral analysis and the statistical distribution ofQfactors across different resonator geometries. Our work pushes the fabrication limits of TFLN photonics to achieve aQfactor within 1 order of magnitude of the material limit.
more »
« less
- Award ID(s):
- 2137723
- PAR ID:
- 10526280
- Publisher / Repository:
- Optical Society of America
- Date Published:
- Journal Name:
- Photonics Research
- Volume:
- 12
- Issue:
- 8
- ISSN:
- 2327-9125
- Format(s):
- Medium: X Size: Article No. A63
- Size(s):
- Article No. A63
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Abstract Low propagation loss in high confinement waveguides is critical for chip‐based nonlinear photonics applications. Sophisticated fabrication processes which yield sub‐nm roughness are generally needed to reduce scattering points at the waveguide interfaces to achieve ultralow propagation loss. Here, ultralow propagation loss is shown by shaping the mode using a highly multimode structure to reduce its overlap with the waveguide interfaces, thus relaxing the fabrication processing requirements. Microresonators with intrinsic quality factors (Q) of 31.8 ± 4.4 million are experimentally demonstrated. Although the microresonators support ten transverse modes only the fundamental mode is excited and no higher order modes are observed when using nonlinear adiabatic bends. A record‐low threshold pump power of 73 µW for parametric oscillation is measured and a broadband, almost octave spanning single‐soliton frequency comb without any signatures of higher order modes in the spectrum spanning from 1097 to 2040 nm (126 THz) is generated in the multimode microresonator. This work provides a design method that can be applied to different material platforms to achieve and use ultrahigh‐Qmultimode microresonators.more » « less
-
Abstract The longwave infrared (LWIR) region of the spectrum spans 8 to 14 μm and enables high-performance sensing and imaging for detection, ranging, and monitoring. Chip-scale LWIR photonics has enormous potential for real-time environmental monitoring, explosive detection, and biomedicine. However, realizing technologies such as precision sensors and broadband frequency combs requires ultra low-loss and low-dispersion components, which have so far remained elusive in this regime. Here, we use native germanium to demonstrate the first high-quality microresonators in the LWIR. These microresonators are coupled to partially-suspended Ge waveguides on a separate glass chip, allowing for the first unambiguous measurements of isolated linewidths. At 8 μm, we measured losses of 0.5 dB/cm and intrinsic quality (Q) factors of 2.5 × 105, nearly two orders of magnitude higher than prior LWIR resonators. Our work portends the development of novel sensing and nonlinear photonics in the LWIR regime.more » « less
-
We demonstrate telecommunication-wavelength Pockels electro-optic modulators in thin-film lithium tantalate (TFLT) with superior DC stability compared to equivalent thin-film lithium niobate (TFLN) modulators. Less than 1 dB output power fluctuation for quadrature-biased TFLT is measured compared to 5 dB with TFLN over 46 hours with 12.1 dBm input power. Our TFLT modulators maintain properties similar to those in TFLN: 3.4 Vcm half-wave voltage length product, 39 dB extinction ratio, flat RF electro-optic response from 3-50 GHz, and 0.35 dB on-chip loss. We also show low error-rate data modulation over 0-70°C with TFLT modulators and optical loss of 9 dB/m.more » « less
-
Ultraviolet and visible integrated photonics enable applications in quantum information, sensing, and spectroscopy, among others. Few materials support low-loss photonics into the UV, and the relatively low refractive index of known depositable materials limits the achievable functionality. Here, we present a high-index integrated photonics platform based on HfO2and Al2O3composites deposited via atomic layer deposition (ALD) with low loss in the visible and near UV. We show that Al2O3incorporation dramatically decreases bulk loss compared to pure HfO2, consistent with inhibited crystallization due to the admixture of Al2O3. Composites exhibit refractive indexnfollowing the average of that of HfO2and Al2O3, weighted by the HfO2fractional compositionx. Atλ = 375 nm, composites withx = 0.67 exhibitn = 2.01, preserving most of HfO2’s significantly higher index, and 3.8(7) dB/cm material loss. We further present fully etched and cladded waveguides, grating couplers, and ring resonators, realizing a single-mode waveguide loss of 0.25(2) dB/cm inferred from resonators of 2.6 million intrinsic quality factor atλ = 729 nm, 2.6(2) dB/cm atλ = 405 nm, and 7.7(6) dB/cm atλ = 375 nm. We measure the composite’s thermo-optic coefficient (TOC) to be 2.44(3) × 10−5RIU/°C nearλ = 397 nm. This work establishes (HfO2)x(Al2O3)1−xcomposites as a platform amenable to integration for low-loss, high-index photonics spanning the UV to NIR.more » « less
