The warning "142 WL calibration failed" is displayed when a level of light source is not enough at wavelength calibration or calibration cannot be executed because wavelength difference is out of calibration range.
There are three suggestions listed below.
After restarting, please try the wavelength calibration again.
With high performance capabilities and a wavelength resolution of 10 picometer or less, the AQ6319 is designed for advanced research and development applications. With a wavelength range or 600 to 1700 nm this OSA offers an excellent combination of wavelength range and resolution.
An Optical Spectrum Analyzer (or OSA) is a precision instrument designed to measure and display the distribution of power of an optical source over a specified wavelength span. An OSA trace displays power in the vertical scale and the wavelength in the horizontal scale.
Optical test equipment or optical measuring instruments are used to measure and characterize the physical properties of light.