The fundamental mode of an optical fiber isThe fundamental mode of an optical fiber isa. a.HE11 modeb. b.TM01 modec. c.LP11d. d.TE01 mode

Break Down the Problem

1. Identify the modes of optical fibers listed in the options.
2. Determine which of these corresponds to the fundamental mode.

Relevant Concepts

• Optical fibers support different propagation modes, primarily categorized as Hybrid (HE), Transverse Electric (TE), and Transverse Magnetic (TM).
• The fundamental mode is the lowest order mode that can propagate through the fiber.

Analysis and Detail

1. HE11 mode: This is a hybrid mode and is often considered for its low loss characteristics in step-index fibers, but it is not typically classified as the fundamental mode.
2. TM01 mode: This transverse magnetic mode is higher than the fundamental mode and has more propagating characteristics.
3. LP11 mode: This is a linearly polarized mode, which is usually a higher order mode rather than the fundamental one.
4. TE01 mode: This transverse electric mode is also a higher order mode than the fundamental mode.

Verify and Summarize

The fundamental mode of an optical fiber is generally recognized as the LP01 mode (not listed in your options), implying that from the remaining choices, the one closest could be the HE11, but it is still not the standard classification.

Final Answer

The fundamental mode is often considered as the LP01 mode; from the provided options, none directly corresponds to the fundamental mode, but option (a) HE11 mode is the closest.