Green Monochromatic Lamps are an ideal light source for testing the flatness of polished optical surfaces. The 12W and 16W lamps contain two uncoated fluorescent bulbs. Cosmetic imperfections on the window may exist but they do not affect performance.
The green light of these lamps enhances the contrast of interference rings, and helps eliminate eye fatigue. Each window is composed of two plastic sheets, one diffusing white sheet, and one transparent green sheet which passes only the green 546.1nm line of the mercury spectrum. Each Green Monochromatic Lamp is tilted forward at a 120° angle of diffusion, allowing uniform illumination over the surface of interest, and can be suspended with a chain for various mounting configurations.