A method for manufacturing an optical device (1, 100), the method comprising a) providing a plurality of bars referred to as initial bars, each initial bar extending along a respective initial-bar direction from a first bar end to a second bar end and having a first side face extending from the first bar end to the second bar end, a first optical component arrangement being present at the first side face; b) positioning the initial bars in a row with their respective initial-bar directions aligned parallel to each other and with their respective first side faces facing towards a neighboring one of the initial bars; c) fixing the plurality of initial bars with respect to each other in the position achieved in step b) to obtain a bar arrangement; the method further comprising d0) obtaining bars referred to as prism bars by carrying out at least one of steps d), d'): d) segmenting the bar arrangement into the prism bars each of which comprises a portion of at least two different ones of the plurality of initial bars, by conducting a plurality of cuts through the bar arrangement; d') segmenting the bar arrangement into the prism bars by separating the bar arrangement into sections along cut lines, wherein the cut lines are at an angle of between 20° and 75° with respect to the initial-bar directions; wherein the segmenting the bar arrangement into the prism bars comprises dx) dividing the first optical component arrangement for obtaining a plurality of passive optical components, wherein each of the prism bars comprises one or more of the passive optical components comprising a first reflective face each which is of non-planar shape; the method further comprising e) segmenting the prism bars into parts; and wherein step c) comprises attaching the initial bars to a first substrate comprising at least one protrusion protruding between neighboring initial bars in the bar arrangement; and wherein the protrusion functions as a baffle (b1, b3) in the optical device (1, 100). a) providing a plurality of bars referred to as initial bars, each initial bar extending along a respective initial-bar direction from a first bar end to a second bar end and having a first side face extending from the first bar end to the second bar end, a first optical component arrangement being present at the first side face; b) positioning the initial bars in a row with their respective initial-bar directions aligned parallel to each other and with their respective first side faces facing towards a neighboring one of the initial bars; c) fixing the plurality of initial bars with respect to each other in the position achieved in step b) to obtain a bar arrangement; the method further comprising d0) obtaining bars referred to as prism bars by carrying out at least one of steps d), d'): d) segmenting the bar arrangement into the prism bars each of which comprises a portion of at least two different ones of the plurality of initial bars, by conducting a plurality of cuts through the bar arrangement; d') segmenting the bar arrangement into the prism bars by separating the bar arrangement into sections along cut lines, wherein the cut lines are at an angle of between 20° and 75° with respect to the initial-bar directions; wherein the segmenting the bar arrangement into the prism bars comprises d) segmenting the bar arrangement into the prism bars each of which comprises a portion of at least two different ones of the plurality of initial bars, by conducting a plurality of cuts through the bar arrangement; d') segmenting the bar arrangement into the prism bars by separating the bar arrangement into sections along cut lines, wherein the cut lines are at an angle of between 20° and 75° with respect to the initial-bar directions; wherein the segmenting the bar arrangement into the prism bars comprises dx) dividing the first optical component arrangement for obtaining a plurality of passive optical components, wherein each of the prism bars comprises one or more of the passive optical components comprising a first reflective face each which is of non-planar shape; the method further comprising e) segmenting the prism bars into parts; and wherein step c) comprises attaching the initial bars to a first substrate comprising at least one protrusion protruding between neighboring initial bars in the bar arrangement; and wherein the protrusion functions as a baffle (b1, b3) in the optical device (1, 100). wherein step c) comprises attaching the initial bars to a first substrate comprising at least one protrusion protruding between neighboring initial bars in the bar arrangement; and wherein the protrusion functions as a baffle (b1, b3) in the optical device (1, 100).