1. What is Diffraction Limit?

The diffraction limit is a fundamental concept in optics that describes the maximum resolution achievable by an optical system due to the wave nature of light. It represents the smallest angular separation at which two point sources can be distinguished.

2. How Does the Calculator Work?

The calculator uses the diffraction limit formula:

Where:

• \( 1.22 \) — Constant derived from the first zero of the Bessel function
• \( \text{Wavelength} \) — Wavelength of the light (meters)
• \( \text{Diameter} \) — Diameter of the aperture or lens (meters)

Explanation: The formula shows that resolution improves with shorter wavelengths and larger apertures. The constant 1.22 comes from the first minimum of the Airy disk pattern.

3. Importance of Diffraction Limit Calculation

Details: Understanding diffraction limits is crucial for designing optical systems like telescopes, microscopes, and cameras. It helps determine the maximum resolution achievable and guides equipment selection for specific applications.

4. Using the Calculator

Tips: Enter wavelength and diameter in meters. Both values must be positive numbers. The result is given in radians, which can be converted to arcseconds by multiplying by 206265.

5. Frequently Asked Questions (FAQ)

Q1: Why is the constant 1.22 used?
A: The constant 1.22 comes from the first zero of the Bessel function of the first kind, which describes the Airy disk pattern formed by a circular aperture.

Q2: How does wavelength affect diffraction limit?
A: Shorter wavelengths result in better resolution (smaller diffraction limit). This is why electron microscopes and X-ray telescopes can achieve higher resolution than visible light instruments.

Q3: What's the relationship between aperture size and resolution?
A: Larger apertures reduce the diffraction limit, allowing for better resolution. This is why large telescopes can resolve finer details than smaller ones.

Q4: Can diffraction limit be overcome?
A: While fundamental, techniques like adaptive optics, interferometry, and super-resolution microscopy can effectively surpass the classical diffraction limit in certain applications.

Q5: How do I convert radians to arcseconds?
A: Multiply the result in radians by 206265 to get the diffraction limit in arcseconds (1 radian = 206265 arcseconds).