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Diffraction Grating Angle Calculator

Diffraction Grating Equation:

\[ \theta = \arcsin\left(\frac{m \lambda}{d}\right) \]

(integer)
nm
µm

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1. What is the Diffraction Grating Equation?

The diffraction grating equation describes the angles at which light is diffracted when passing through a grating. It's fundamental in spectroscopy and optical physics for analyzing light properties.

2. How Does the Calculator Work?

The calculator uses the diffraction grating equation:

\[ \theta = \arcsin\left(\frac{m \lambda}{d}\right) \]

Where:

Explanation: The equation calculates the angle at which constructive interference occurs for light of a specific wavelength passing through a grating with a given line spacing.

3. Importance of Diffraction Angle Calculation

Details: Accurate angle calculation is crucial for designing optical instruments, spectroscopy applications, and understanding light-matter interactions.

4. Using the Calculator

Tips: Enter diffraction order (integer), wavelength in nanometers, and grating spacing in micrometers. The calculator will return the diffraction angle in degrees.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical grating spacing value?
A: Common gratings have 300-1200 lines/mm (d = 3.33-0.83 µm). Holographic gratings may have even finer spacing.

Q2: Why does the calculator show an error sometimes?
A: The equation requires |mλ/d| ≤ 1. If this condition isn't met, no real solution exists for that combination of parameters.

Q3: What's the difference between positive and negative orders?
A: Positive and negative orders appear symmetrically on opposite sides of the central maximum (m=0).

Q4: How does wavelength affect the diffraction angle?
A: Longer wavelengths diffract at larger angles, which is why white light spreads into a spectrum.

Q5: Can this be used for transmission and reflection gratings?
A: Yes, the basic equation applies to both, though reflection gratings may have additional geometric factors.

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