(color online) Cross-sectional plots of time-averaged optical force-density components ⟨F_x⟩, ⟨F_y⟩, and ⟨F_z⟩, through central planes of 450-nm-diameter SD fiber with oblique endface. 980-nm fundamental mode (i.e., HE₁₁ mode) with quasi-y polarization is excited at z = 0 μm and propagates along SD fiber (whose length occupies the range from z = 0 μm to z = 4 μm). Plots of calculated optical force density correspond to incident optical power P_inc = 3.06 × 10⁻¹⁶ W. Color scale bar shows force density in units of μN/m³. (a) ⟨F_x⟩, (b) ⟨F_y⟩, (c) ⟨F_z⟩, respectively in central xz plane (y = 0 μm). ⟨F_x⟩, ⟨F_y⟩, and ⟨F_z⟩, respectively in xy plane with z = 1.3 μm (second row, i.e., (d)–(f)), z = 1.92 μm (third row, i.e., (g)–(i)), z = 2.74 μm (fourth second row, i.e., (j)–(l)), z = 3.255 μm (bottom row, i.e., (m)–(o)). The dashed line represents the profile of the SD fiber.