PHYC30080 Optics & Lasers

Academic Year 2020/2021

This module addresses fundamentals of optics and lasers in four themes:
Theme 1. Propagation of light, the basics
Theme 2. Rays and Lasers, a unified matrix approach
Theme 3. The Fourier transform in optics and lasers
Theme 4. Coherence and spectroscopy

Weekly workshops address problems in sync with lectures.

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Curricular information is subject to change

Learning Outcomes:

The student acquires an understanding of geometric optics, laser optics, Fourier methods and spectroscopy that is transportable across technologies, industries and fields of science.

Indicative Module Content:

Propagation of light
Complex numbers, phasors, waves and wave-equations, refractive index. Refraction, reflection, TIR, Fermat, Intro to behavior of transmission and reflection for polarized light.

Rays and Lasers, a unified matrix approach.
Equations for transmission and reflection for polarized light, Pointing, irradiance. Geometric optics and rays, ray tracing, optical systems, 2x2 matrices for ray propagation: free propagation, lens, flat and curved interface, curved mirror, curved interface, duct. Derivations for curved interface, lens maker’s formula, matrix for thick lens. Introduction to principle planes. Geometric aberrations. Laser beam analysis using matrices. Laser beam analysis using matrices. Laser action and pulsing. Fourier series and Fourier transform, Complex Fourier transform in space or time, optical Fourier transform using a lens. Fourier transforms of summed functions, Gaussian function.

The Fourier transform in optics and lasers.
Delta function, spatial displacement transforming to a linear phase and visa-versa. The scaling theorem. Considering a lens in f-f¬ arrangement and propagation to the far-field as optical Fourier transforms. Deriving propagation to the far-field as an FT using the idea of wavelets. Fourier transforms of rectangular function (slit), cylinder function (cf. PSF for circular aperture later in course). Superposition, temporal shifts/linear phase in frequency, sine and cosine functions considered as interference between slits and considered in time-frequency space. Convolution, Convolution theorem: its derivation and applications in one and two dimensions e.g., mechanical, optical transfer function. Convolution theorem examples: atomic emission spectrum, mode-locked laser operation in time and frequency. Fourier transformation with a 4-f telescope and spatial filtering. Group and phase velocity, dispersion.

Coherence in spectroscopy and light propagation.
Coherence and visibility. Fundamental understanding of spectrometers and considering Michelson, Etalon, Grating. Strehl, revisiting far-field (Fraunhoffer limit), slit aperture/rectangular aperture. Fresnel zone plate. Resolving Power, Finesse, resolution, Rayleigh and Sparrow criteria.

Student Effort Hours: 
Student Effort Type Hours
Lectures

22
Small Group

10
Specified Learning Activities

44
Autonomous Student Learning

44
Total

120
Approaches to Teaching and Learning:
Workshops (WS)
One workshop is held each week. These sessions involve problem solving and they can involve an introduction of concepts too. These sessions are synchronized with lectures that build upon the topics introduced. Physics shouldn’t be about learning just by rote. In some cases you will be challenged to deduce things and there can be a problem for tying up as homework afterwards.

Homework assignments
Pace homework. Do these near to the time assigned and ask me any questions at that time. Selected questions from homework are graded for each theme.

Questions and pacing your work
I encourage you to ask me anything during/after any lecture or workshop or when you see my office door open. Don't put back homework and the questions that arise from it. Instead, be sure to pace your work during teaching semester, doing homework and workshop problems around the time assigned and be sure to close out any questions with me at that time. This leads to a more efficient and improved learning. I am not readily available for helping with problem solving outside of teaching semester.
 
Requirements, Exclusions and Recommendations
Learning Requirements:

Irish/UK/US introductory-level maths for university engineering/physics, or equivalent level, to include: algebra, geometry, trigonometry, integral and differential calculus of algebraic and trigonometric functions including up to second-order differential equations

Learning Recommendations:

PHYC 20010


Module Requisites and Incompatibles
Not applicable to this module.
 
Assessment Strategy  
Description Timing Open Book Exam Component Scale Must Pass Component % of Final Grade
Examination: Written exam at end of semester 2 hour End of Trimester Exam No Graded No

50
Continuous Assessment: Homework Varies over the Trimester n/a Graded No

50

Carry forward of passed components
No
 
Resit In Terminal Exam
Summer Yes - 2 Hour
Please see Student Jargon Buster for more information about remediation types and timing. 
Feedback Strategy/Strategies

• Group/class feedback, post-assessment

How will my Feedback be Delivered?

Graded homework is returned to you on Bpsace. We have a live post-discussion/Q&A on each homework in a following class session.

The course materials are contained in our lectures, workshops and homework, so be sure to attend and complete all of these components during teaching semester. You are assessed on these materials. No one book covers the course but the following sources provide for a reference in relation to the course materials: a) Hecht, ‘Optics’; b) Born and Wolf, ‘Principles of Optics’; c) Siegman, ‘Lasers’.