Search for: All records

Photonic funnels have been demonstrated as a flexible platform to confine light to deep subwavelength spatial areas. Here we consider the utility of this platform to provide temporal, as well as spatial, light shaping. 

In this Rapid Community Report - Process Reflection, the STEM PUSH Network (Pathways for Underrepresented Students to HigherEd), an NSF INCLUDES Alliance, describes a root cause analysis process used to build the conceptual foundation of the improvement network and establish a shared vision and clear roles for the partnership. Four layers of reflection, including internal evaluation, external evaluation, advisory council review, and an NSF reverse site visit, surfaced the need for and strategies to strengthen equity and youth agency in the root cause analysis process. 

In integrated photonics, specific wavelengths such as 1,550 nm are preferred due to low-loss transmission and the availability of optical gain in this spectral region. For chip-based photodetectors, two-dimensional materials bear scientifically and technologically relevant properties such as electrostatic tunability and strong light–matter interactions. However, no efficient photodetector in the telecommunication C-band has been realized with two-dimensional transition metal dichalcogenide materials due to their large optical bandgaps. Here we demonstrate a MoTe2-based photodetector featuring a strong photoresponse (responsivity 0.5 A W–1) operating at 1,550 nm in silicon photonics enabled by strain engineering the two-dimensional material. Non-planarized waveguide structures show a bandgap modulation of 0.2 eV, resulting in a large photoresponse in an otherwise photoinactive medium when unstrained. Unlike graphene-based photodetectors that rely on a gapless band structure, this photodetector shows an approximately 100-fold reduction in dark current, enabling an efficient noise-equivalent power of 90 pW Hz–0.5. Such a strain-engineered integrated photodetector provides new opportunities for integrated optoelectronic systems.