Adjustable-focus ultracompact endoscopic lens design with ultrahigh optical performance.

Area of Science:

• Optical engineering
• Biomedical optics
• Medical imaging technology

Background:

• Endoscopic procedures require high-resolution imaging.
• Current endoscopic lenses face limitations in maintaining optical quality across different working distances.
• Compactness is crucial for endoscopic device maneuverability.

Purpose of the Study:

• To develop an internally focusing compact endoscopic lens with near-diffraction-limit optical performance.
• To maintain constant system length and field of view while adjusting working distance.
• To demonstrate the feasibility of adjustable focus for high-resolution endoscopic examinations.

Main Methods:

• Development of an internally focusing lens design.
• Numerical demonstration of optical performance across a range of working distances.
• Lens configuration analysis (PNN: positive-negative-negative power groups).
• Tolerance analysis for the proposed lens design.

Main Results:

• The internally focusing endoscopic lens design achieves near-diffraction-limited optical performance.
• Constant system length and field of view are maintained during focus adjustment.
• Diffraction-limited performance is sustained over a wide range of working distances.
• A four-element PNN lens configuration is identified as effective for high-resolution imaging.

Conclusions:

• The novel internally focusing endoscopic lens design is numerically feasible.
• This design offers a significant advancement for high-resolution endoscopic examinations.
• The ability to capture clear images at varying working distances enhances diagnostic capabilities for biological entity examination.