... 2,Measure laser gain in the intracavity. F-HX1020 He-Ne Laser and Laser ResonanceExperiment contents and related subjects: ... equipment: Optical experiment guide, semiconductor laser, semi-internal cavity He-Ne laser, beam expander mirror, two-dimensional adjustable mold piece ... meter (optional), oscilloscope (self) and etc. Gas laser He-Ne laser 0.8mw 632.8nm laser Optical experimental equipment