LUMINAIRE

1 . A lighting fixture, comprising:

a main housing elongated in a longitudinal direction;

a light source for emitting light, the light source supported by the main housing;

an elongated member of light-permeable material supported by the main housing and configured to receive the light emitted by the light source, the member being elongated in the longitudinal direction and including a first wall having a distal edge, a second wall oriented parallel to the first wall and having a distal edge, and a light-emitting surface extending between the distal edge of the first wall and the distal edge of the second wall, the light-emitting surface having elongated prisms extending parallel to the longitudinal direction for refracting the light; and

a reflecting surface elongated in the longitudinal direction and at least partially facing the light-emitting surface for reflecting light refracted by the elongated member.

2 . The lighting fixture of claim 1 , wherein the elongated member includes a recess for receiving the light source or a plurality of recesses for receiving a plurality of light sources, wherein the recess or the plurality of recesses extend in the longitudinal direction.

3 . The lighting fixture of claim 1 , wherein the light-emitting surface is oriented. in a plane extending between the distal edge of the first wall and the distal edge of the second wall.

4 . The lighting fixture of claim 3 , wherein the main housing includes an opening for emitting light, the opening being disposed in an output plane, and wherein the plane of the light-emitting surface is oriented at an acute angle relative to the output plane.

5 . The lighting fixture of claim 1 , wherein the prisms are at least approximately right angle prisms.

6 . A lighting fixture, comprising:

a main housing elongated in a longitudinal direction and having an elongated opening;

a light source supported by the main housing; and

a elongated member of light-permeable material supported by the main housing and receiving light emitted by the light source, the light tube being elongated in the longitudinal direction and including a first wall having a distal edge, a second wall oriented parallel to the first wall and having a distal edge, and a light-emitting surface extending along a plane between the distal edge of the first wall and the distal edge of the second wall in a step-like manner, the light-emitting surface having a plurality of elongated prisms extending in the longitudinal direction for refracting the light from the light source.

7 . The lighting fixture of claim 6 , further comprising a reflecting surface at least partially facing the light-emitting surface for receiving the refracted light and reflecting the refracted light towards the opening.

8 . The lighting fixture of claim 7 , wherein the reflecting surface is generally planar and elongated in the longitudinal direction.

9 . The lighting fixture of claim 6 , wherein the main housing is generally cuboid with at least one open face defining the opening.

10 . The lighting fixture of claim 6 , wherein the opening is disposed in an output plane, and wherein the light-emitting surface is transverse to the output plane.

11 . The lighting fixture of claim 10 , wherein the light-emitting surface is disposed at about 40 to about 50 degrees with respect to the output plane.

12 . The lighting fixture of claim 6 , wherein the light-emitting surface has a plurality of elongated prisms extending in the longitudinal direction for refracting the light from the light source prisms, the elongated prisms being at least approximately right angle prisms.

13 . An optic for refracting light in a lighting fixture, the optic comprising:

a body of light-permeable material elongated in a longitudinal direction and including,

a first sidewall including a distal edge,

a second sidewall oriented parallel to the first sidewall and including a distal edge,

a light-emitting surface extending between the distal edge of the first sidewall and the distal edge of the second sidewall, the light-emitting surface extending along a plane forming an acute angle relative to at least one of the first wall and the second wall, the light-emitting surface having generally linear, elongated prisms extending in the longitudinal direction for refracting the light,

wherein the body is configured to internally transmit light entering a light-receiving surface of the body, and

wherein the body is longer in the longitudinal direction than in a direction generally perpendicular to the longitudinal direction from the base to the light-emitting surface

14 . The optic of claim 13 , wherein the first sidewall and the second side wall each protrude from a base, the first sidewall having a height relative to the base that is greater than a height of the second sidewall relative to the base.

15 . The optic of claim 13 , wherein the prisms are at least approximately right angle prisms.

16 . The optic of claim 13 , wherein the base further includes a recess or a plurality of recesses for receiving the light source, wherein the recess or the plurality of recesses extend in the longitudinal direction.

17 . The optic of claim 16 , wherein the recess or the plurality of recesses defines the light-receiving surface, and wherein the light-receiving surface has a generally cylindrical shape or a generally semi-spherical shape.

18 . The optic of claim 17 , wherein the base further includes two base flanges extending in the longitudinal direction for mourning the light tube.

19 . The optic of claim 13 , wherein the light-emitting surface is transverse to the base.

20 . The optic of claim 13 , herein the light-emitting surface includes about 20-25 prisms per inch.