railway route selection；railway location；approximate railway location；location of railway route selection
Ar + laser and 532 nm laser
Ar(+) laser and 532 nm laser
Ar(+) laser and 532nm laser
Ar~+ laser and 532 nm laser
Ar+ laser and 532 nm laser
continuous wave laser CW gas laser
continuous wave laser CW laser
diode laser pumped solid-state laser
four-energy-level laser (=four level laser)
helium neon laser (=He-Ne laser)
laser diode diode laser
Laser diode double-pumped solid-state laser
Laser diode pumped alkali laser
laser diode pumped solid state laser