The LWCC features optical sample cells with an increased optical path length (50 – 500 cm) and fiber optic capabilities. feature: to include someone or something asan important part (以……为主). Its patented (专利的) aqueous waveguide technology enables increased optical pathlengths in 1m (LPC-100 cm), 2m (LPC-200 cm) and 5m (LPC-500 cm) for absorbance measurements compared with a standard 1 cm cell. According to Lambert-Beer Law, the absorbance signal is proportional to chemical concentration and opticalpath length. With an increased light path length, the absorbance of low-volume or low-concentration (ppb-ppt) aqueous samples can be measured. The LWCC functions with most liquids (exceptfor perfluorinated 全氟化的 solvents) having a refractive index>=1.30.

In the field of ocean optics, LWCC is a good choice for in situ measurements of CDOM absorbance when connected to a light source and a spectrometer. Below is a picture of a LWCC system used for measuring CDOM absorbance. Generally, the LWCC connects with fiber optic cables to the light source and to the fiber optic spectrometers (光纤光谱仪) via SMA terminations (SMA 接头). Light is confined within the liquid coreof an LWCC by total internal reflection at the core/wall interface. With a pump and a 0.22 um filter, filtered seawater (CDOM) samples can be pumped and injected into the LWCC, absorb light from the lamp (UV/VIS/NIR) with the residual light signal from the lamp detected by the fiber optic spectrometer, thus obtaining the absorbance of CDOM.

Extensions

Fiber Optics

The basic principle of light transport through an opticalfiber is total internal reflection. That is, the light within the numerical aperture (NA, 数值孔径) of a fiber will be reflected andtransported through the fiber.

SMA terminations/connectors

SMA is short for Sub Miniature A. SMA connectors are used for fiber optics.  They are screw fitted and can be rotated over 360 degrees.