Study Material
How energy and matter interact is at the very foundation of physics. We will explore two of the most important aspects of such interactions, as well as developing skills in experimental physics. First, we will study optics, the properties of light and its interactions with matter. We will focus on the wave nature of light and effects such as refraction, diffraction and interference. In our second module we will study thermodynamics, a subject central to many branches of science, with applications from the smallest systems of atoms to the big bang. We will examine the concepts such as entropy, thermodynamic interactions, engines and heat. In the experimental physics module students will carry out in-depth experiments, each one spanning several weeks, building experimental skills. These skills will include the measurement of physical quantities; analysing data; assessing reliability and significance; and communicating scientific results. Experimental topics include the nature of light, the properties of matter, electrical circuits, astrophysics and others.
Learning Outcomes
Week 1:
The importance of Optics and Photonics
Understand the difference between Geometrical v. Physical v. Quantum optics
Geometrical Optics – review of basic topics
Reflection, Image formation from reflective surfaces
Week 2:
Understand refraction and image formation from refractive media
Learn the lens equation and its physical meaning/usage
Total Internal Reflection and Dispersion of light
Learn the foundations of Wave Optics and wave representation including plane waves and spherical waves
Discuss Ray Optics vs Wave Optics;
Learn about Rayleigh Scattering, Reflection, Refraction, lenses in the wave optics framework;
Huygens’ principle
Week 3:
Coherence of Light
understand and discuss the concept of spatial coherence, and use it to explain why fringes will not be seen from twin slits with unsuitable (incoherent) illumination
understand and discuss the concept of the temporal coherence length of light, and calculate the coherence length as a function of the centre wavelength and range of wavelengths detected
Interference - Double slit with slits of non-zero width
discuss and apply the Fraunhofer intensity pattern formed by a double slit where the slits have a non-zero width.
be able to sketch the intensity distribution illustrating the relative widths of the interference fringes and the central diffraction envelope
Interference in Thin Films
discuss the formation of interference fringes in light reflected from thin films
recognise the π phase change that occurs when reflection occurs at a boundary where the refractive index increases
explain and use the equation for net phase difference of the combining rays, as a function of the film thickness, the refractive indices of the film and surrounding media, and the wavelength of the light
use the phase difference between combining rays to find whether the rays undergo constructive, destructive or partial interference
discuss the formation of fringes of equal thickness (contour fringes) in non-uniform thin films
discuss single layer anti-reflection coatings and be able to relate the thickness of such a film to the refractive indices of the coating and coated material and to the wavelength of incident light
Week 4:
discuss the formation of fringes of equal thickness in uniform thin films
understand the relationship of the fringe spacing to the refractive indices of the film and surrounding media, the thickness of the film, and the wavelength of the light
The Michelson Interferometer and other types of interferometers
discuss the formation of interference fringes in an amplitude splitting interferometer
draw the layout of a Michelson interferometer with representative reflected and transmitted light rays, and explain the function and operation of the interferometer
describe some examples of amplitude splitting interferometers and their applications.
discuss the Mach–Zehnder, Sagnac and the Fabry–Perot interferometers
Diffraction by single slit
recognise and apply the Fraunhofer diffraction pattern for multiple slits and explain the effect on the pattern of increasing the number of slits [36.4]
describe transmission and reflection diffraction gratings and their use in spectrometers [36.5]
apply the equation for angle of diffraction as a function of diffraction order, wavelength, and slit separation
understand and use the terms angular dispersion
Week 5
Interference and Diffraction - Double slit with slits of non-zero width
discuss and apply the Fraunhofer intensity pattern formed by a double slit where the slits have a non-zero width, giving a single-slit diffraction envelope which modulates the peak intensity of two-source interference fringes within the envelope
be able to sketch the intensity distribution illustrating the relative widths of the interference fringes and the central diffraction envelope
explain the effects on the Fraunhofer diffraction pattern of changing the width of the slits, the separation of the slits, or the wavelength of the light
Diffraction by Multiple Slits
recognise and apply the Fraunhofer diffraction pattern for multiple slits and explain the effect on the pattern of increasing the number of slits
Week 6
Diffraction by Multiple Slits II
describe transmission and reflection diffraction gratings and their use in spectrometers
apply the equation for angle of diffraction as a function of diffraction order, wavelength, and slit separation
understand and use the terms angular dispersion and chromatic resolving power as applied to diffraction gratings
Diffraction from Circular Apertures
recognise the Fraunhofer diffraction pattern for a circular aperture and be able to draw the intensity distribution pattern illustrating the relative scales of the central and secondary maxima
apply the dependence of the angular scale of the Fraunhofer diffraction pattern (as given by the location of the first intensity minimum) for a circular aperture on the diameter of the aperture and on the wavelength of the light
define and apply Rayleigh’s criterion for resolution to circular apertures
Polarisation
define what is meant by unpolarised, plane polarised, circularly polarised, and partially polarised light
appreciate that the phenomena of polarisation show that light is a transverse wave
understand and discuss the use of polarising filters (such as Polaroid) to produce linearly polarised light
apply Malus’ law relating the intensity transmitted by a polarising filter to the angle between the plane of incident polarisation and the transmission axis
understand and discuss the production of polarised light by specular reflection at non-metallic surfaces, with complete linear polarisation at the Brewster angle
Birefringence
understand and discuss the phenomena of birefringence and its effect on polarized waves
understand and discuss the concept of ordinary and extraordinary waves in birefringent materials
explain how a quarter wave plate works
describe what is meant by the term circular polarisation
Week 7
Birefringence
understand and discuss the phenomena of birefringence and its effect on polarized waves
understand and discuss the concept of ordinary and extraordinary waves in birefringent materials
explain how a quarter wave plate works
describe what is meant by the term circular polarisation [33.5]
1st and 2nd Law of thermodynamics
ideal gas law
energy partition
1st Law of thermodynamics
Heat engine
2nd law of thermodynamics
Week 8
Probabilistic approach to entropy
Concepts of microstates and macrostates
Definition/understanding of entropy in terms of probability & multiplicity
Einstein solid with 3 oscillators
2 Einstein solids
Boltzmann hypothesis
Sackur-Tetrode Equation for entropy
Entropy for a monoatomic ideal gas
Partition of space using Heisenberg Uncertainty Principle
Sackur-Tetrode Equation
Isothermal and quasistatic expansion (or compression)
Free Expansion into a vacuum
Mixing of 2 gases
Reversible and Irreversible processes
Week 9
Equilibrium & 1st thermodynamic identity
Internal energy (U) and entropy (S) relationship to pressure (P), temperature (T) and volume (V)
Thermal Equilibrium
Entropy and energy flow
Mechanical Equilibrium
Thermodynamic Identity
First Law, Heat, & Entropy
Reversible and irreversible examples
Week 10
Chemical potential & applications of 1st thermodynamic identity
Chemical potential
Diffusive equilibrium
Thermodynamic Identity including chemical potential
Chemical potential for an ideal gas
Chemical potential for an Einstein solid
Chemical potential change at different heights
Enthalpy, Helmholotz & Gibbs free energies
Enthalpy H
Enthalpy relationship to Heat and work
Helmholtz Free Energy F
Gibbs Free Energy G
Thermodynamic Potentials
Extraction of Heat and Work
Week 11
Thermodynamic potentials & 2nd law
Examples using H,F, and G
Electrolysis of water
Reversal of Electrolysis of Water
Hydrogen Fuel Cell
Derive generalised thermodynamic identities
Redefine the Second Law in terms of Free Energy
Phase diagrams & phase transitions
Phase changes
Phase diagrams
Stability and changes in phase with T and P
Gibbs Free Energy & Phase Diagrams
Variations in G with T and P
Clausius-Claperyon Relation: dP/dT,
Entropy changes, volume changes, and latent heats
Week 12
Solutions and osmotic pressure
Chemical Potential
Gibbs Free Energy of a mixture
Gibbs Free Energy & Entropy of mixing
Chemical potential for dilute solutions/mixtures
Chemical potential & molality
Osmosis
Stopping Osmosis
Changing Boiling Points
Thermodynamics of black holes
Schwarzschild radius
Entropy of Black Holes
Temperature of Black Holes
Evaporation of Black Holes