A detection system is used during irradiation of an interaction region of
a structure including embedded material with laser light. The detection
system includes a collimating lens positioned to receive light emitted
from the interaction region. The detection system further includes an
optical fiber optically coupled to the collimating lens and a
spectrometer optically coupled to the optical fiber. The spectrometer is
adapted for analysis of the light for indications of the embedded
material within the interaction region. The spectrometer includes an
input slit adapted to receive light from the optical fiber. The input
slit has a width selected to provide sufficient light transmittance and
sufficient resolution. The spectrometer further includes an optical
grating adapted to receive light from the input slit and to separate the
light into a spectrum of wavelengths. The spectrometer further includes a
collection lens adapted to receive a selected range of wavelengths of the
separated light from the optical grating. The spectrometer further
includes a light sensor adapted to receive the selected range of
wavelengths and to generate a signal corresponding to an intensity of the
received light.