Advanced Higher Physics

Knowledge that two waves are coherent if they have a constant phase relationship.

Knowledge of the conditions for constructive and destructive interference in terms of coherence and phase.

Use of an appropriate relationship to solve problems involving optical path difference opd, geometrical path difference gpd and refractive index.

\mathrm{opd}=n\times \mathrm{gpd}

Knowledge that a wave experiences a phase change of p when it is travelling in a less dense medium and reflects from an interface with a more dense medium.

Knowledge that a wave does not experience a phase change when it is travelling in a more dense medium and reflects from an interface with a less dense medium.

Explanation of interference by division of amplitude, including optical path length, geometrical path length, phase difference, and optical path difference.

Knowledge of thin film interference and wedge fringes.

For light interfering by division of amplitude, use of an appropriate relationship to solve problems involving the optical path difference between waves, wavelength and order number.

\mathrm{opd}=\mathrm{m\lambda } or \mathrm{(m\; +}\frac{1}{2}\mathrm{)\lambda } where m = 0, 1, 2...

Knowledge that a coated (bloomed) lens can be made non-reflective for a specific wavelength of light.

Derivation of the relationship d=\frac{\lambda }{\mathrm{4n}} for glass lenses with a coating such as magnesium fluoride.

Use of appropriate relationships to solve problems involving interference of waves by division of amplitude.

\mathrm{\Delta x}=\frac{\mathrm{\lambda l}}{\mathrm{2d}}

d=\frac{\lambda }{\mathrm{4n}}

Explanation of interference by division of wavefront.

Knowledge of Young’s slits interference.

Use of an appropriate relationship to solve problems involving interference of waves by division of wavefront.

\mathrm{\Delta x}=\frac{\mathrm{\lambda D}}{d}