Lightguide lamp with crosstalk prevention

Abstract

The invention provides a light generating system () comprising one or more light generating devices (), a lightguide element (), and an optical filter (), wherein: (A) the one or more light generating devices () are configured to generate device light (); (B) the lightguide element () comprises a light transmissive body () comprising light transmissive material (), which is light transmissive for the device light (); wherein the light transmissive body () comprises an axis of elongation () and a body length (L), wherein the light transmissive body () comprises a first end () and a second end (); wherein the light transmissive body () comprises (i) a first outer face (), comprised by the first end (), (ii) a second outer face (), comprised by the second end (), and (iii) an external side face () bridging a distance between the first outer face () and the second outer face () and having a distance (d) to the axis of elongation (); (D) the optical filter () is configured downstream of the first light generating device () and upstream of the first outer face (), wherein the optical filter () has a higher transmission for the first luminescent material light () than for a wavelength selected from the at least partially spectrally overlapping wavelength range (SO); and (E) the light generating devices () and the lightguide element (), are configured such that (i) at least part of the device light () is coupled in the lightguide element () via the first outer face (), (ii) at least part of the incoupled device light () escapes from the lightguide element () via the external side face () and/or via the second outer face ().