Which of the following best describes the term "coherent" in relation to laser light?

Which of the following best describes the term "coherent" in relation to laser light?

• A. Light waves are of different wavelengths
• B. Light waves are all in phase and of the same frequency
• C. Light waves travel in random directions
• D. Light waves are scattered

Answer: (B)

The term "coherent" in relation to laser light refers to the property where light waves are all in phase and of the same frequency. This means that the peaks and troughs of the light waves align consistently over time, resulting in a stable and defined interference pattern. Coherence is a key characteristic of laser light, which is what allows lasers to produce highly focused and intense beams. In contrast, options describing light waves of different wavelengths or traveling in random directions do not relate to the definition of coherence. Light that is incoherent would lack these properties, leading to diffuse, non-uniform illumination rather than the sharp and focused beams characteristic of lasers. Similarly, scattering of light indicates that the wavefronts are disrupted and no longer maintain a consistent phase relationship, which is not indicative of coherence. Thus, the option that defines coherence as having light waves that are all in phase and of the same frequency is the correct description.

The term "coherent" in relation to laser light refers to the property where light waves are all in phase and of the same frequency. This means that the peaks and troughs of the light waves align consistently over time, resulting in a stable and defined interference pattern. Coherence is a key characteristic of laser light, which is what allows lasers to produce highly focused and intense beams.

In contrast, options describing light waves of different wavelengths or traveling in random directions do not relate to the definition of coherence. Light that is incoherent would lack these properties, leading to diffuse, non-uniform illumination rather than the sharp and focused beams characteristic of lasers. Similarly, scattering of light indicates that the wavefronts are disrupted and no longer maintain a consistent phase relationship, which is not indicative of coherence. Thus, the option that defines coherence as having light waves that are all in phase and of the same frequency is the correct description.