Fig. 1. Illumination range of LED fishing lamps

Fig. 2. Relationship between the divergent angle of 110° and the effective irradiation angle of 90° of LED fishing lamp under different rolling angles. (a) Boat tilting to the left; (b) boat not rolling; (c) boat tilting to the right

Fig. 3. Divergence angle of LED fishing lamp. (a) Fan-shaped divergence angle is 110° on the Y-Z cross-section; (b) small divergence angle on the X-Y cross-section

Fig. 4. Package of LED chips. (a) 3D model of LED module; (b) distribution of LED chips

Fig. 5. Schematic of the cross-section of optical system and light path

Fig. 6. Ray tracing on the first surface and second surface of Y-Z cross-section

Fig. 7. Ray tracing on the first surface and second surface of X-Y cross-section

Fig. 8. Structure of the free-form lens. (a) 3D model of the lens; (b) Y-Z cross-section of the lens; (c) fabricated free-form lens sample

Fig. 9. Light intensity distribution of LED fishing lamps in Y-Z plane and X-Y plane

Fig. 10. Illuminance distribution on the target surface under different illumination angles. (a) 0°; (b) -10°; (c) -5°; (d) 5°; (e) 10°

Fig. 11. Experiment measurement. (a) Field illumination effect; (b) location of the test points

Fig. 12. Simulated and experimental relative illumination distributions on the target plane along Y-axis direction at different illumination angles. (a) 0°; (b) -10°; (c) -5°; (d) 5°; (e) 10°

Fig. 13. Pictures of fishing lamp. (a) Improved LED fishing lamp; (b) ordinary LED fishing lamp^[10]; (c) metal halide lamp

Fig. 14. Flux distribution curves of fishing lamp. (a) Improved LED fishing lamp; (b) ordinary LED fishing lamp^[10]; (c) metal halide lamp

Fig. 15. Relative illuminance distribution of fishing lamp. (a) Improved LED fishing lamp; (b) ordinary LED fishing lamp^[10]; (c) metal halide lamp