These characteristics work together: ➤ Wavelength: Source wavelength should match the fiber's low-loss windows for best transmission. ➤ Power & NA: Enough source power and high fiber NA allow for efficient light coupling. ➤ Linewidth & Dispersion: Narrower linewidth reduces signal distortion from dispersion in the fiber. ➤ Bandwidth: Source modulation bandwidth should be less than or equal to the fiber bandwidth to avoid data rate limitations.