Direct laser writing (DLW) has been shown to render 3D polymeric optical components, including lenses, beam expanders, and mirrors, with submicrometer precision. However, these printed structures are limited to the refractive index and dispersive properties of the photopolymer. Here, we present the subsurface controllable refractive index via beam exposure (SCRIBE) method, a lithographic approach that enables the tuning of the refractive index over a range of greater than 0.3 by performing DLW inside photoresist-filled nanoporous silicon and silica scaffolds. Adjusting the laser exposure during printing enables 3D submicron control of the polymer infilling and thus the refractive index and chromatic dispersion. Combining SCRIBE’s unprecedented index range and 3D writing accuracy has realized the world’s smallest (15 µm diameter) spherical Luneburg lens operating at visible wavelengths. SCRIBE’s ability to tune the chromatic dispersion alongside the refractive index was leveraged to render achromatic doublets in a single printing step, eliminating the need for multiple photoresins and writing sequences. SCRIBE also has the potential to form multicomponent optics by cascading optical elements within a scaffold. As a demonstration, stacked focusing structures that generate photonic nanojets were fabricated inside porous silicon. Finally, an all-pass ring resonator was coupled to a subsurface 3D waveguide. The measured quality factor of 4600 at 1550 nm suggests the possibility of compact photonic systems with optical interconnects that traverse multiple planes. SCRIBE is uniquely suited for constructing such photonic integrated circuits due to its ability to integrate multiple optical components, including lenses and waveguides, without additional printed supports.

Background: The first wave of the COVID-19 pandemic affected health in all domains i.e., physical, mental, and social aspects. Liver transplant (LT) recipients faced a multitude of challenges during the first wave of lockdown. The aim was to identify the psychosocial difficulties and quality of life during the first year of the pandemic. Methods: A cross-sectional survey was conducted on LT recipients with a predefined structured questionnaire that included clinical, COVID-19 anxiety scale, and Post-Transplant Quality of life questionnaire (pLTQ). Results: A total of 109 patients were studied; with a mean age of 50.5 ± 11.1 years, with a median post-transplant follow-up of 52.4 months and a live donor transplant in the majority (79.8%). Almost all (99.1%) could come to the hospital for regular follow-up, prior to the pandemic. But during the first wave only 57% could maintain planned hospital visits and about 88% could not pursue their regular activities, and 39% missed their routine exercise because of imposed restrictions. Similarly, financial implications were responsible for 4% defaulting from treatment; while 7.3% managed by curtailing supportive drugs (on their own) leading to deranged liver tests in 4.6%; requiring immediate attention. The psychosocial difficulties raised the stress of pandemic (median score 18), and impacted quality of life (mean total pLTQ score 4.7 ± 0.9) Conclusions: For LT recipients, the first wave of COVID-19 pandemic affected their physical, mental, financial, and social wellbeing; in addition to the disease itself. Awareness, psychosocial support, and comprehensive care are some unmet needs for this special group; especially when it is expected that subsequent waves may continue to occur.

No abstract

No abstract

No abstract