A method for selecting a test optical fiber for use in testing one or more optical transmitter, the method comprising the steps of: for the test optical fiber determining: a desired effective modal bandwidth " EMB D "; a percentage of allowable variation of the EMB D " A "; a desired length " L D "; a percentage of allowable variation of the L D " B "; a tolerance variable "X"; and a desired total bandwidth BW, where BW = EMB D L D; selecting a candidate optical fiber, wherein the candidate optical fiber is a graded index multimode optical fiber; obtaining an effective modal bandwidth of the candidate optical fiber " EMB sp "; rejecting the candidate optical fiber when EMB sp ≥ EMB D ( 1+A+B) is true or when EMB sp ≤ EMB D ( 1-A-B-X) is true; cutting the candidate optical fiber to a first length L 1, where L 1 = L D (1+ B), when EMB sp ≥ EMB D (1+ A + B) is false and when EMB sp ≤ EMB D ( 1-A-B-X) is false; measuring an effective modal bandwidth of the candidate optical fiber cut to the first length L 1 ( EMB m1); accepting the candidate optical fiber cut to the first length L 1 as the test optical fiber when BW 1 − A ≤ EMB m 1 L 1 ≤ BW 1 + A is true; performing additional evaluation steps when BW 1 − A ≤ EMB m 1 L 1 ≤ BW 1 + A is false, the additional evaluation steps including: rejecting the candidate optical fiber cut to the first length L 1 when EMB m 1 L D 1 + B ≤ 1 − A is false or when EMB m 1 L D 1 − B ≥ BW 1 − A is false; cutting the candidate optical fiber cut to the first length L 1 down to a second length L 2, where L 2 = max (( EMB m 1 / BW), L D (1- B)) when EMB m 1 L D 1 + B ≤ BW 1 − A is true and when EMB m 1 L D 1 − B ≥ BW 1 − A is true; measuring an effective modal bandwidth of the candidate optical fiber cut to the second length L 2 ( EMB m2); rejecting the candidate optical fiber cut to the second length L 2 when BW 1 − A ≤ EMB m 2 L 2 ≤ BW 1 + A is false; and accepting the candidate optical fiber cut to the second length L 2 as the test optical fiber when BW 1 − A ≤ EMB m 2 L 2 ≤ BW 1 + A is true. for the test optical fiber determining: a desired effective modal bandwidth " EMB D "; a percentage of allowable variation of the EMB D " A "; a desired length " L D "; a percentage of allowable variation of the L D " B "; a tolerance variable "X"; and a desired total bandwidth BW, where BW = EMB D L D; a desired effective modal bandwidth " EMB D "; a percentage of allowable variation of the EMB D " A "; a desired length " L D "; a percentage of allowable variation of the L D " B "; a tolerance variable "X"; and a desired total bandwidth BW, where BW = EMB D L D; selecting a candidate optical fiber, wherein the candidate optical fiber is a graded index multimode optical fiber; obtaining an effective modal bandwidth of the candidate optical fiber " EMB sp "; rejecting the candidate optical fiber when EMB sp ≥ EMB D ( 1+A+B) is true or when EMB sp ≤ EMB D ( 1-A-B-X) is true; cutting the candidate optical fiber to a first length L 1, where L 1 = L D (1+ B), when EMB sp ≥ EMB D (1+ A + B) is false and when EMB sp ≤ EMB D ( 1-A-B-X) is false; measuring an effective modal bandwidth of the candidate optical fiber cut to the first length L 1 ( EMB m1); accepting the candidate optical fiber cut to the first length L 1 as the test optical fiber when BW 1 − A ≤ EMB m 1 L 1 ≤ BW 1 + A is true; performing additional evaluation steps when BW 1 − A ≤ EMB m 1 L 1 ≤ BW 1 + A is false, the additional evaluation steps including: rejecting the candidate optical fiber cut to the first length L 1 when EMB m 1 L D 1 + B ≤ 1 − A is false or when EMB m 1 L D 1 − B ≥ BW 1 − A is false; cutting the candidate optical fiber cut to the first length L 1 down to a second length L 2, where L 2 = max (( EMB m 1 / BW), L D (1- B)) when EMB m 1 L D 1 + B ≤ BW 1 − A is true and when EMB m 1 L D 1 − B ≥ BW 1 − A is true; measuring an effective modal bandwidth of the candidate optical fiber cut to the second length L 2 ( EMB m2); rejecting the candidate optical fiber cut to the second length L 2 when BW 1 − A ≤ EMB m 2 L 2 ≤ BW 1 + A is false; and accepting the candidate optical fiber cut to the second length L 2 as the test optical fiber when BW 1 − A ≤ EMB m 2 L 2 ≤ BW 1 + A is true. rejecting the candidate optical fiber cut to the first length L 1 when EMB m 1 L D 1 + B ≤ 1 − A is false or when EMB m 1 L D 1 − B ≥ BW 1 − A is false; cutting the candidate optical fiber cut to the first length L 1 down to a second length L 2, where L 2 = max (( EMB m 1 / BW), L D (1- B)) when EMB m 1 L D 1 + B ≤ BW 1 − A is true and when EMB m 1 L D 1 − B ≥ BW 1 − A is true; measuring an effective modal bandwidth of the candidate optical fiber cut to the second length L 2 ( EMB m2); rejecting the candidate optical fiber cut to the second length L 2 when BW 1 − A ≤ EMB m 2 L 2 ≤ BW 1 + A is false; and accepting the candidate optical fiber cut to the second length L 2 as the test optical fiber when BW 1 − A ≤ EMB m 2 L 2 ≤ BW 1 + A is true.