Illumination apparatus with optimized light distribution

An illumination apparatus, comprising:

• a housing;
• at least one light source mounted on the housing and adapted to emit light into a first hemisphere centered about an optical axis forming a first optical distribution, the optical axis being oriented in a downward direction;
• a refractor element having a body portion surrounding the at least one light source and extending about the optical axis, the body portion defining a bottom opening;
• and
• a bottom lens disposed across at least a portion of the bottom opening to substantially enclose the bottom opening,
• wherein
• the bottom lens includes a central portion having an inward protruding profile extending towards the at least one light source,
• at least a first portion of the first optical distribution is transmitted through the bottom lens into the first hemisphere, and at least a second portion of the first optical distribution is reflected by the bottom lens to form a second optical distribution directed in an upward direction into a second hemisphere opposite the first hemisphere,
• a ratio of a total luminous flux emitted by the illumination apparatus with the bottom lens to a total luminous flux emitted in absence of the bottom lens is at least 0.90, 0.95, or 0.98.

An illumination apparatus, comprising:

• a housing;
• at least one light source mounted on the housing and adapted to emit light into a first hemisphere centered about an optical axis forming a first optical distribution, the optical axis being oriented in a downward direction;
• a refractor element having a body portion surrounding the at least one light source and extending about the optical axis, the body portion defining a bottom opening;
• and
• a bottom lens disposed across at least a portion of the bottom opening to substantially enclose the bottom opening,
• wherein
• the bottom lens includes a central portion having an inward protruding profile extending towards the at least one light source,
• at least a first portion of the first optical distribution is transmitted through the bottom lens into the first hemisphere, and at least a second portion of the first optical distribution is reflected by the bottom lens to form a second optical distribution directed in an upward direction into a second hemisphere opposite the first hemisphere,
• a ratio (hmax/w) of a maximum protrusion height (h) to a lateral width (w) of the bottom lens is at least 0.10, 0.20, 0.30, 0.40 or 0.50.