1. What is Gaussian Beam Waist?

The Gaussian beam waist (w₀) is the radius of the laser beam at its narrowest point, where the beam is most concentrated. It's a fundamental parameter in laser optics that describes the minimum beam diameter.

2. How Does the Calculator Work?

The calculator uses the Gaussian beam waist equation:

Where:

• \( w_0 \) — Beam waist radius (m)
• \( \lambda \) — Wavelength of the laser (m)
• \( z_R \) — Rayleigh range (m)

Explanation: The equation shows that the beam waist depends on both the wavelength of light and the Rayleigh range, which characterizes how quickly the beam diverges.

3. Importance of Beam Waist Calculation

Details: Knowing the beam waist is crucial for laser applications like microscopy, optical trapping, laser cutting, and fiber coupling. It determines the intensity profile and focusing characteristics of the laser beam.

4. Using the Calculator

Tips: Enter the wavelength in meters and Rayleigh range in meters. Both values must be positive numbers. For typical lasers, wavelengths are often in nanometers (1 nm = 10^-9 m).

5. Frequently Asked Questions (FAQ)

Q1: What is the relationship between beam waist and beam divergence?
A: The beam waist and divergence angle are inversely related - a smaller waist leads to greater divergence, and vice versa.

Q2: How does wavelength affect the beam waist?
A: Longer wavelengths generally produce larger beam waists for the same focusing conditions due to diffraction effects.

Q3: What is the Rayleigh range?
A: The distance over which the beam radius remains within √2 of the minimum value (waist). It characterizes the depth of focus.

Q4: Can this be used for non-Gaussian beams?
A: No, this equation is specific to fundamental-mode Gaussian beams. Higher-order modes have different intensity profiles.

Q5: How is beam waist measured experimentally?
A: Common methods include knife-edge scans, CCD camera profiling, or measuring the beam diameter at multiple positions.