The ornamental design for an optical timedomainreflectometer, as shown and described.
FIG. 1 is a front view of an optical time domain reflectometer, showing my new design;
FIG. 2 is a rear view thereof;
FIG. 3 is a left view thereof;
FIG. 4 is a right view thereof;
FIG. 5 is a top view thereof;
FIG. 6 is a bottom view thereof;
FIG. 7 is a front perspective view thereof; and,
FIG. 8 is a rear perspective view thereof.
The button names “MENU”, “ESC”, “AVG”, “REAL TIME”, and “Enter” depicted in FIG. 1 and FIG. 7 merely represent written matter surface ornamentation which does not form any part of the claimed design.