We report on Terahertz quantum cascade lasers with tapered waveguide structure operating at ≈ 103 μm. The tapered waveguide effect on the output power and the laser beam divergence are experimentally studied with the tapered angle ranging from 0° to 8°. It is found that the peak output power of the devices with same length reaches the maximum at about 5° ≈ 6° tapered angle. Meanwhile, the horizontal divergence angle of the laser beam can be greatly reduced. The existence of such optimal tapered angle is explained by the finite-element simulation with the consideration of the self-focusing effect for the devices with larger tapered angle.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1364/OE.21.015998 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Fabrication of nonplanar tapered fibers to integrate optical and electrical signals for neural interfaces in vivo.
Nat Protoc
January 2025
Center for Biomolecular Nanotechnologies, Istituto Italiano di Tecnologia, Arnesano, Italy.
Implantable multifunctional probes have transformed neuroscience research, offering access to multifaceted brain activity that was previously unattainable. Typically, simultaneous access to both optical and electrical signals requires separate probes, while their integration into a single device can result in the emergence of photogenerated electrical artifacts, affecting the quality of high-frequency neural recordings. Among the nontrivial strategies aimed at the realization of an implantable multifunctional interface, the integration of optical and electrical capabilities on a single, minimally invasive, tapered optical fiber probe has been recently demonstrated using fibertrodes.
View Article and Find Full Text PDFMicrogap Formation in Conical Implant-Abutment Connections Under Oblique Loading: Influence of Cone Angle Mismatch Through Finite Element Analysis.
Clin Implant Dent Relat Res
February 2025
Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, Minneapolis, Minnesota, USA.
Objectives: This study evaluated different designs of the conical implant-abutment connection (IAC) and their resistance to microgap formation under oblique loads as specified by the ISO standard for testing dental implants. Also evaluated was the effect of deviations from the ISO specifications on the outcomes.
Methods: Finite element analysis was conducted to compare the microgap formation and stress distribution among three conical IAC designs (A, B, and C) in two loading configurations: one compliant with ISO 14801 and one with a modified load adaptor (non-ISO).
Travoprost Intracameral Implant in Eyes with Glaucoma or Ocular Hypertension: Early Short-Term Real-World Outcomes.
Clin Ophthalmol
January 2025
Harvard Eye Associates, Laguna Hills, CA, USA.
Purpose: To assess real-world efficacy and safety of standalone travoprost intracameral implant (iDose TR) implantation by a US glaucoma surgeon in patients with open-angle glaucoma (OAG) or ocular hypertension (OHT).
Methods: This non-randomized, retrospective, unmasked, consecutive case series included all cases of standalone iDose TR implantation from a single US glaucoma surgeon since the product's approval by the US Food and Drug Administration (FDA) in December 2023. Patients were pseudophakic, had OAG or OHT, and had undergone prior SLT and/or bimatoprost intracameral implant injection (Durysta).
We present both experimental and simulation results for a fully etched, C-band GC fabricated in an 800 nm silicon nitride platform that significantly reduces backreflections. They are minimized by truncating the initial grates, which deflect reflected light at an oblique angle and excite higher-order modes in the tapered waveguide that is filtered out. Insertion losses resulting from this modification of the grating coupler are mitigated by an adaptive redesign of the grates that corrects incurred errors in the generated phase front.
View Article and Find Full Text PDFEvaluation of Retentive Force and Long-Term Performance of 4 Mol% Yttria Partially Stabilized Zirconia (4Y-PSZ) Double Crowns.
Cureus
December 2024
Department of Prosthodontics, Graduate School of Dentistry, Showa University, Tokyo, JPN.
Purpose: This study aims to evaluate the effects of taper angle and the number of insertion-removal cycles on the retention force of 4 mol% yttria partially stabilized zirconia (4Y-PSZ) double crowns over time.
Materials And Methods: Primary and secondary crowns were fabricated using 4Y-PSZ with taper angles of 2°, 4°, and 6° (n=15). Retention force during crown removal was measured after applying 50-N and 100-N loads.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!