Both of these lasers do the same thing—they both project crisp, bright, visible lines (or dots) that are easily controllable and directional. What makes them different is how they produce the light. The Helium-Neon (HeNe) gas laser produces a red beam by passing light through a gas-filled (HeNe) tube. The solid state diode laser produces a red beam by passing light through a wafer. The other primary differences are size and cost. Our technological advancements have permitted us to build a smaller better laser that is more economical to build, operate and maintain.