Usb4000 vis nir

Diffuse reflectance spectrophotometry, which measures the light reflected by objects as a function of wavelength, has been widely employed to evaluate the color of biological and artificial pigments [46 (link)]. For the colored sticky traps, their spectral reflectance (without the acetate and the glue) was determined by a visible-infrared spectrophotometer (USB4000-VIS-NIR, Ocean Optics, Orlando, FL) with an optical resolution of 1.5 nm (full width at half maximum). Even though our spectrometer provided readings down to 350nm the readings between 350 and 375nm were noisy and not reliable, therefore the reliable range of 375 to 1000nm was considered for this work (Fig 2). The illumination of sticky traps was performed with a tungsten-halogen light source (LS-1, Ocean Insight, Orlando, FL). Both the illumination and the reflected light were provided and collected respectively using a fiber-optic reflection probe (R200-7-VIS-NIR, Ocean Optics, Orlando, FL). Measurements were performed using a 1s integration time. The raw reflectance spectra were corrected to eliminate the dark current and normalized with the spectrum obtained from the light source reflected on a Teflon white standard reference [47 (link)].

In order to capture the spectral intensities of the transmittance through an apple, an acquisition system was configured with a laptop computer, spectrometer (USB4000-VIS-NIR, Ocean Optics, Orlando, FL, USA), the fixture for transmittance measurement, two types of light sources (i.e., the developed and TH lamp) as shown in Figure 2d,e. In terms of optical layout, the light source was located at the equatorial level of an apple, where the VIS/NIR radiation passes through it. At the underneath of the apple, the measurement fixture was placed with an optical probe with a collimator lens, which is connected to an optical fiber. In terms of its optical pathway, the transmitted light from the left side of an apple is measured at the optical probe in the right side, which is connected to USB4000-VIS-NIR spectrometer with an optical slit width of approximately 200 µm.

The reflectance spectroscopy of butterfly Trogonoptera brookiana wings and the SiO₂ negative replica were measured using a miniature fiber optic spectrometer (Ocean Optics USB4000-VIS-NIR) equipped with a halogen tungsten lamp source (Ocean Optics LS-1-LL). The spot size of the incident beam was ~2 mm, and the wavelength of the reflectance spectroscopy varied in the range of 400–900 nm. In addition, the element types and content analysis of the surface of the SiO₂ negative replica were characterized by virtue of the energy dispersive spectroscopy (EDS, OXFORD X-Max^N 150) on the SEM.