Analyzer alignment, sample detection, localization, and focusing method and system
An analysis (e.g., LIBS) system includes a source of radiation, an optical emission path for the radiation from the source of radiation to a sample, and an optical detection path for photons emitted by the sample. A detector fiber bundle transmits photons to the spectrometer subsystem. At least one fiber of the fiber bundle is connected to an illumination source (e.g., an LED) for directing light via at least a portion of the detection path in a reverse direction to the sample for aligning, sample presence detection, localizing, and/or focusing based on analysis of the resulting illumination spot on the sample.
1. An analysis method comprising:
directing a laser beam from a source of radiation along an emission path to create a mark on a sample;
directing photons emitted by the sample along a detection path including a detection fiber bundle having a common end located to receive said photons emitted by the sample;
directing light from an illumination source coupled to a fiber of the fiber bundle via at least a portion of the detection path to the sample creating an illumination spot thereon; and
analyzing the illumination spot on the sample for aligning the position of the detection fiber bundle common end based on the illumination spot by adjusting the position of the detection fiber bundle common end until the illumination spot is concentric with the mark created on the sample.
2. The method of claim 1 in which aligning further includes focusing the laser beam on the sample by adjusting the position of the fiber bundle common end until the size of the illumination spot is minimized.
3. The method of claim 1 in which the sample is a tape and the mark is a hole created through the tape.
4. The method of claim 1 in which the sample includes a substrate and the mark is a crater in the substrate.