Colour compound lenses for a portable fluorescence microscope

Abstract

In this article, we demonstrated a handheld smartphone fluorescence microscope (HSFM) that integrates dual-functional polymer lenses with a smartphone. The HSFM consists of a smartphone, a field-portable illumination source, and a dual-functional polymer lens that performs both optical imaging and filtering. Therefore, compared with the existing smartphone fluorescence microscope, the HSFM does not need any additional optical filters. Although fluorescence imaging has traditionally played an indispensable role in biomedical and clinical applications due to its high specificity and sensitivity for detecting cells, proteins, DNAs/RNAs, etc., the bulky elements of conventional fluorescence microscopes make them inconvenient for use in point-of-care diagnosis. The HSFM demonstrated in this article solves this problem by providing a multifunctional, miniature, small-form-factor fluorescence module. This multifunctional fluorescence module can be seamlessly attached to any smartphone camera for both bright-field and fluorescence imaging at cellular-scale resolutions without the use of additional bulky lenses/filters; in fact, the HSFM achieves magnification and light filtration using a single lens. Cell and tissue observation, cell counting, plasmid transfection evaluation, and superoxide production analysis were performed using this device. Notably, this lens system has the unique capability of functioning with numerous smartphones, irrespective of the smartphone model and the camera technology housed within each device. As such, this HSFM has the potential to pave the way for real-time point-of-care diagnosis and opens up countless possibilities for personalized medicine.

Integrated polarizers based on graphene oxide in waveguides and ring resonators

“…Moreover, GO based polarizers have simpler designs with higher fabrication tolerance as compared with silicon photonic polarizers. Indeed, the latter require precise design and control of the dimensions [2,3]. It is also interesting to note that the PDL slightly increases at longer wavelengths for both the uniformly coated and patterned devices.…”

“…Polarization control is one of the fundamental requirements in many optical technologies [1][2][3]. Polarization selective devices, such as polarizers and polarization selective resonant cavities (e.g., gratings and ring resonators), are core components for polarization control in optical systems and find wide applications in polarization-division-multiplexing [4,5], coherent optical detection [6,7], photography [8,9], liquid crystal display [10,11], and optical sensing [12,13].…”

“…To implement polarization-selective devices, a number of schemes have been proposed and demonstrated, including those based on refractive prisms [14,15], birefringent crystals [16,17], fiber components [18][19][20], and integrated waveguides [21][22][23][24][25]. Among them, integrated polarization-selective devices based on complementary metal-oxide-semiconductor (CMOS) compatible integrated platforms [26] offer advantages of compact footprint, high stability, mass producibility, and high scalability as functional building blocks for photonic integrated circuits (PICs) [2]. Optical waveguides with metal cladding have been widely used to implement waveguide polarizers [27,28].…”

Compact broadband low-loss taper for coupling to a silicon nitride photonic wire

“…We experimentally demonstrate taper insertion loss of <0.1 dB/transition for a taper as short as 19.5 µm, and reduces the footprint of the photonic device by 50.8% compared to the standard adiabatic taper. To the best of our knowledge, the proposed taper is the shortest waveguide taper ever reported in Silicon Nitride.Large-scale photonic integrated circuits (PICs) provide immense potential to meet the anticipated requirements of ultrafast computing, communication and sensing applications [1][2][3]. In particular, CMOS compatible materials such as Silicon, Germanium, and Silicon Nitride have evolved to address key application space such as high-speed interconnects, Mid-IR and visible-broadband photonics.…”

“…Large-scale photonic integrated circuits (PICs) provide immense potential to meet the anticipated requirements of ultrafast computing, communication and sensing applications [1][2][3]. In particular, CMOS compatible materials such as Silicon, Germanium, and Silicon Nitride have evolved to address key application space such as high-speed interconnects, Mid-IR and visible-broadband photonics.…”