Optical Lenses
Definition: Optical lenses are transparent components (usually made of glass or plastic) that refract light to converge or diverge beams, used in imaging, focusing, and beam shaping.
Types of Lenses
- Convex Lens (Converging): Thicker at the center; focuses parallel rays to a point. Used in magnifiers, cameras, and telescopes.
- Concave Lens (Diverging): Thinner at the center; spreads out light. Used in correcting myopia and laser beam expansion.
- Plano-Convex / Plano-Concave: One flat surface; used in collimating or focusing light in optical systems.
- Double Convex / Double Concave: Both surfaces curved; for short focal length applications.
- Aspheric Lens: Non-spherical surface; reduces aberrations. Ideal for high-precision optics like camera lenses.
- Cylindrical Lens: Curved in one direction; shapes laser lines or corrects astigmatism.
- Ball Lens: Spherical lens; used in fiber coupling and endoscopy.
Key Parameters
| Parameter | Description |
|---|
| Focal Length | Distance from lens to focal point. |
| NA (Numerical Aperture) | Light-gathering ability; higher NA = better resolution. |
| Material | Glass (e.g., BK7, fused silica), plastic; affects transmission & dispersion. |
| Coating | AR (anti-reflective) coatings reduce reflections and increase transmission. |
Applications