Coincident Imaging and Spectrometric Observations of Zenith OH Nightglow Structure
During the ALOHA-90 campaign a novel comparative study was made between near infrared wave structure imaged in the zenith using a CCD camera and that detected at infrared wavelengths by a Fourier Transform Spectrometer. Coincident measurements were made briefly on several occasions and for an extended period on 31 March. The temporal variations imaged in the near infrared structure during this night almost completely matched those detected in the OH (3,1) band spectrometer data when similar viewing fields were compared. However, the image data also displayed small scale wave forms that were not resolved by the larger field instrument. These structures exhibited significant changes in brightness and position on a time scale much shorter than the local Brunt-Vaisala period indicating that very high resolution measurements are necessary to investigate short period (<20 min) upper atmospheric wave motions.
Spatial and Temporal Stability of Airglow Measured in the Meinel Band Window at 1191.3 nm
We report on the temporal and spatial fluctuations in the atmospheric brightness in the narrow band between Meinel emission lines at 1191.3 nm using a λ/Δλ = 320 near-infrared instrument. We present the instrument design and implementation, followed by a detailed analysis of data taken over the course of a night from Table Mountain Observatory. At low airmasses, the absolute sky brightness at this wavelength is found to be 5330 ± 30 nW m−2 sr−1, consistent with previous measurements of the inter-band airglow at these wavelengths. This amplitude is larger than simple models of the continuum component of the airglow emission at these wavelengths, confirming that an extra emissive or scattering component is required to explain the observations. We perform a detailed investigation of the noise properties of the data and find no evidence for a noise component associated with temporal instability in the inter-line continuum. This result demonstrates that in several hours of ∼100 s integrations the noise performance of the instrument does not appear to significantly degrade from expectations, giving a proof of concept that near-infrared line intensity mapping may be feasible from ground-based sites.
Application of 2μm Tm Laser on Biomedicine
Continuous wave Thulium laser emits at wavelength of 2.0 mm, which is well suited for tissue ablationand thermally stimulating cutaneous nerves due to its high absorption by water. 2 mm laser can be transmitted suffi-ciently by common quartz fibers and it is safe for eyes. A brief introduction of principle of 2 mm CW Tm Laser is giv-en, analyzing the photothermal modeling of thulium laser-tissue interaction, comparing 2 mm CW Tm Laser with tradi-tional laser.