Related Experiment Video
Updated: Oct 19, 2025
13:51
Synthesis of Core-shell Lanthanide-doped Upconversion Nanocrystals for Cellular Applications
Published on: November 10, 2017
15.6K
Core-shell NaErF4@NaYF4 upconversion nanoparticles qualify as a NIR speckle wavemeter for a visible CCD
Tianliang Wang1, Yi Li1, Long Yan2
1College of Optical and Electronic Technology, China Jiliang University, Hangzhou 310018, China. yli@cjlu.edu.cn.
Nanoscale
|September 21, 2021
Summary
This study introduces a compact, low-cost near-infrared (NIR) wavemeter using a novel scattering waveguide and a convolutional neural network (CNN). The device achieves ultra-high wavelength precision for laser measurements.
Area of Science:
- Optics and Photonics
- Materials Science
- Machine Learning
Background:
- Speckle patterns are used for precise monochromatic light wavelength determination.
- Existing optical diffusing waveguides face challenges in balancing cost, compactness, precision, and stability.
Purpose of the Study:
- To design a compact, cost-effective, and high-precision near-infrared (NIR) wavemeter.
- To overcome the imaging limitations of visible cameras in the NIR range.
Main Methods:
- Developed a compact cylindrical random scattering waveguide (CRSW) using TiO2 particles and UV adhesive.
- Integrated upconversion nanoparticles (UCNPs) to convert NIR to visible light.
- Designed a convolution neural network (CNN) for wavelength recognition from speckle patterns.
Main Results:
- Achieved high wavelength precision of 20 kHz (∼0.16 fm) at 1550 nm.
- Demonstrated good temperature stability with resistance to ±2 °C.
- The CRSW-UCNP system effectively converts NIR to visible light for imaging.
Conclusions:
- The developed NIR wavemeter is low-cost, compact, and simple.
- It offers ultra-high wavelength precision and good temperature stability.
- Significant potential for high-speed and high-precision laser wavelength measurements.
Related Concept Videos
01:25IR Spectrometers
1.6K
There are two main infrared (IR) spectrophotometers: dispersive IR spectrometers and Fourier transform infrared (FTIR) spectrometers. In a dispersive IR spectrometer, a beam of infrared radiation produced by a hot wire is divided into two parallel equal-intensity beams using mirrors. One beam passes through the sample, while another is a reference beam. The beams then move through the monochromator, which separates the radiations into a continuous spectrum of different frequencies. The...
1.6K
01:09Infrared (IR) Spectroscopy: Overview
3.1K
When electromagnetic radiation passes through a material, atoms or molecules transition from a lower to a higher energy state by absorbing radiation corresponding to the energy difference between the two states. The absorption of infrared (IR) radiation causes transitions between vibrational energy levels in a molecule. Therefore, IR spectroscopy is a useful analytical tool for determining the molecular structure of molecules.
Different compounds display unique properties due to their...
Different compounds display unique properties due to their...
3.1K
01:05Total Internal Reflection Fluorescence Microscopy
9.3K
Total internal reflection fluorescence microscopy or TIRF is an advanced microscopic technique used to visualize fluorophores in samples close to a solid surface with a higher refractive index, such as a glass coverslip. TIRF only allows fluorophores in proximity to the solid surface to be excited. When light from a medium with a lower refractive index (such as air) hits the glass coverslip at a critical angle, the light undergoes total internal reflection stead of passing through the glass.
9.3K
01:22Atomic Emission Spectroscopy: Instrumentation
705
The instrumentation of atomic emission spectrometry (AES) involves various components, including atomization devices that convert samples into gas-phase atoms and ions. There are two main types of atomization devices: continuous and discrete atomizers. Continuous atomizers, like plasmas and flames, introduce samples in a constant stream, while discrete atomizers inject individual samples using syringes or autosamplers. The most common discrete atomizer is the electrothermal atomizer.
705
01:25Fluorescence and Phosphorescence: Instrumentation
920
Fluorometers and spectrofluorometers are two types of instruments used for measuring molecular fluorescence. These instruments differ in how they select excitation and emission wavelengths and the type of light sources they utilize. Fluorometers use absorption interference filters to choose excitation and emission wavelengths. The excitation source in a fluorometer is typically a low-pressure mercury vapor lamp that emits intense lines distributed throughout the ultraviolet and visible regions.
920
01:14Photoluminescence: Applications
555
Photoluminescence offers a wide range of applications due to its inherent sensitivity and selectivity. This technique allows for both direct and indirect analyses of the analyte. Direct quantitative analysis is possible when the analyte exhibits a favorable quantum yield for fluorescence or phosphorescence. However, an indirect analysis may be feasible if the analyte is not fluorescent or phosphorescent, or if the quantum yield is unfavorable. Indirect methods include reacting the analyte with...
555