Differences Between Ordinary Light and Laser Light

What is Ordinary Light?

Ordinary light is a mixture of electromagnetic waves of different wavelengths, which is perceived by our eyes as a combination of colors.

It can be produced naturally by thermal emission (like sunlight) or other spontaneous processes.

What is Laser Light?

Laser light, which stands for Light Amplification by Stimulated Emission of Radiation, is a device that emits a powerful, monochromatic (single color or wavelength) and collimated (focused) beam of light.

Unlike ordinary light, laser light is produced not by spontaneous emission, but by stimulated emission through a specially designed device.

Differences Between Ordinary Light and Laser Light

Here are the main differences between ordinary light and laser light:

1. Nature of Light

Ordinary light is typically produced by natural sources like the sun or artificial sources like incandescent bulbs,

whereas laser light is generated using specialized devices called lasers.

2. Angular Spread

In ordinary light, the angular spread is significantly higher, typically around 1 meter per meter (1m/m).


i.e. for every meter it travels, it spreads by 1m.

On the other hand, laser light exhibits minimal angular spread, typically around 1 millimeter per meter (1ย mm/m), rendering it highly directional.


i.e. for every meter it travels, it spreads by 1mm.

3. Directionality

Ordinary light tends to radiate in all directions, whereas laser light is highly directional, focused into a narrow beam.

4. Intensity

Laser light is characterized by its high intensity, which means itโ€™s very bright and concentrated, while ordinary light generally has lower intensity.

5. Coherence

Ordinary light emits photons with different phases and frequencies, leading to incoherent waveforms.

In contrast, laser light produces coherent beams where photons move in unison (i.e., together), maintaining a fixed phase relationship and frequency.

6. Radiation Characteristics

The radiation emitted by ordinary light is polychromatic, containing a mixture of wavelengths perceived as various colors.

Conversely, laser light is monochromatic, consisting of a single wavelength, thereby producing a distinct, pure color.

7. Examples

Examples of ordinary light sources include sunlight, incandescent bulbs, and fluorescent lights.

Examples of laser light sources include helium-neon (He-Ne) lasers and carbon dioxide (CO2) lasers.


1. How is laser light different from ordinary light?

Laser light is highly directional and coherent, with intense concentration and monochromatic properties, unlike the scattered and polychromatic nature of ordinary light.

2. Can ordinary light be as focused as laser light?

No, ordinary light lacks the inherent directionality and coherence of laser light, making it unable to achieve the same level of focus and precision.

3. Are there any risks associated with using laser light?

Yes, laser light poses potential hazards, including eye injury, skin burns, and material damage, necessitating careful adherence to safety protocols.

4. What are some everyday applications of ordinary light?

Ordinary light sources are ubiquitous in daily life, illuminating homes, offices, streets, and powering various devices, from light bulbs to electronic displays.

5. How do lasers produce such intense beams of light?

Lasers generate intense beams through the process of stimulated emission, wherein photons are amplified and aligned coherently, resulting in concentrated and powerful light output.