PHTN9120: Fundamentals of Light Sources and Lasers
(2014 Fall)



Course Description

The nature of light itself as well as the atomic processes leading to light production, the mechanisms of incoherent light production, as well as the fundamentals of laser action will be examined. Incoherent sources of emission including blackbody radiators, gas discharges, and semiconductor sources will be studied and modeled and spectroscopic emissions analyzed. For an atomic system quantum mechanics will be used to model energy levels and transitions (hence predicting the emission spectrum). Most importantly, the basic mechanics of lasers will be covered including the quantum processes involved, concept of laser gain, excitation mechanisms, and optical resonators. Mathematical models of laser action, based on rate equations, will be developed allowing computation of thresholds (e.g. gain) and prediction of performance. The concept of laser gain and saturation will be examined, both in theory and in the lab. An intensive laboratory component allows students to explore course material in a practical hands-on manner.

Prerequisites

Prerequisites for the program (and hence this course) are an undergraduate University Degree in Physics, Engineering, or a related field. A strong background in physics, exposure to basic optics, and fluency in usage of computers is required as well as the ability to apply algebra and calculus to solve problems.

This course is a prerequisite for PHTN9180 and PHTN9190. Failure to pass either the theory or lab/practical portion of this course will result in ineligibility to progress to these prerequisite courses in the winter term.

This course is equivalent to BATP9301 Laser Systems

Evaluation ...

Three midterm examinations, totalling 60%, as follows ...

Midterm #1 in class
One Hour, in class, worth 15%. Covering Blackbody concepts, atomic emission, spectroscopy, semiconductors (and thermal energy), and quantum mechanics concepts (Chapters 1, 2, and 3 of FLL)
Review held in class prior to the test
Midterm #2 in class
One Hour, in class, worth 15%. Covering, primarily, the gain threshold equation (Chapter 4 of FLL and Chapter 2 of LM) and application to various laser configurations
Review held in class prior to the test
Midterm #3 during week 15 in class
Two hours, in class, worth 30%. Covering applications of theory to real-world problems involving lasers (primarily using gain/loss concepts to develop basic models and predict operating parameters such as gain and output power including use of the Rigrod model)
Do not expect questions testing 'pure theory' such as the first two tests, rather expect concepts such as blackbody radiation to be applied to a practical problem such as determination of required laser gain. It is not an "all encompassing" final exam (there is no "traditional" all-encompassing final exam in this course during exam period) but rather a demonstration of application of learned theory.

Labs and assignments combined for a total of 40%

Course Policies ...

Course policies follow the Standardized Policies and Procedures for CEE (dated January 2011). In summary:

Complete course policies can be found in the Teaching and Learning Plan (T&LP) document found on Blackboard.

Textbooks

There are two textbooks in this course. These same texts will be used next term in PHTN9180 (i.e. you will not have to purchase another text for that course).

Fundamentals of Light Sources and Lasers by Csele, 2004, John Wiley & Sons, ISBN 0-471-47660-9

Chapters 1 to 4 and parts of chapter 5, 6, and 9 are covered in this course. Chapters 1 through 3 outline incoherent light sources and basic quantum mechanics while chapter 4 introduces fundamental concepts of lasers. The rest of the text is covered in the next course.

Laser Modeling: A Numerical Approach with Algebra and Calculus by Csele, 2014, CRC Press, ISBN 9781466582507

Chapters 1 to 4 are covered in this course. Of special interest is chapter 2 which outlines the formulation of the gain threshold equation in great detail, chapter 3 which presents gain saturation and application to modeling a basic laser with respect to output power and other key parameters, and chapter 4 which outlines the Rigrod approach. Other parts of the text will be used extensively in subsequent terms.

Course Notes and Links

Useful Links

Equipment Manuals and SOPs

Laboratories and Assignments

There are five labs in this course. Lab sessions are two-hours in length and individual labs can span up to three consecutive lab periods. Labs for this course emphasize both proficiency in the manual skills required of a technician (e.g. the ability to use laboratory equipment, align optics and lasers, and take measurements of a system to characterize it) and experimental proof of concepts from the lectures. Reports will be submitted for each lab with an emphasis on results and observations.

In line with departmental policies, the lab portion of this course MUST be passed SEPARATELY from the theory portion in order to pass this course. Late labs result in an immediate mark of ZERO with no exceptions and no excuses accepted (including the now infamous "my printer ran out of ink" and "my computer died"). Failure to submit a lab (and a late lab is considered failed and will receive a mark of zero) will result in the student being placed on course condition. Failure to submit a second lab results in immediate EXPULSION from the course.

WARNING: You must pass the lab portion of the course separately from the theory portion in order to pass the course. Submission of late labs, or failure to submit any lab, will result in the student being placed on course condition - subsequent failure to submit labs on-time will result in automatic and immediate expulsion from the course (as discussed on the first day of classes): see the TL&P on Blackboard for details.

NOTE: While observed results (numbers only) may be identical for more than one student, no other portions of the lab are to be shared. Where procedures, analysis, graphs, and/or conclusions are suspected to be plagiarized, labs will be submitted to the dean's office and all students involved will receive a mark of zero. "Sharing" answers and analysis often equates to "Plagiarism" which is academic misconduct and will be treated accordingly.

Spectroscopy & Light Sources Labs:

Lab 0: Introduction

An introductory lab session in which lab groups will be assigned. Several key topics including lab safety, procedures, and lab report format will be covered. As well, requirements for prelab #1 will be reviewed.

On week 2 (Starting 2014/09/xx)

Lab 1: Basic Spectroscopy

The emissions of various light sources are analyzed using two types of grating instruments. Emissions from broadband sources such as incandescent and fluorescent sources are first analyzed using a manual spectroscope, after a suitable (and involved) calibration procedure. In the case of the fluorescent lamp, each observed line and band is assigned to the component source in the lamp. Atomic spectra from several pure gases in spectrum tubes (Hydrogen and Neon) are also analyzed. Finally, students will be given an unknown spectral source (a spectrum tube with an unknown gas) and be required to identify the gas via its spectral emissions using a high-resolution computer-based Ocean Optics spectrograph.

Lab Weighting: 2.0
Part A&B on week 3 (2014/09/xx); Part C&D on week 4 (2014/09/xx)
PRELAB due on entry to first lab period (week 5 starting 2014/09/xx)

Full Lab Report due at the beginning of the lab period on week 5 (2014/09/xx). Failure to submit this lab BEFORE or ON the due date and time will result in an immediate ZERO on the lab and placing of the student on course condition (meaning one more late or missing lab results in immediate EXPULSION from the course without recourse).

Example Lab 1 Marking Scheme example

Lab 2: Determining Planck's Constant

Using spectroscopy and basic electronics the spectral and V/I characteristics of several LEDs are observed. Analysis of the data allows determination of Planck's constant. Using the same technique, the unknown emission wavelength of an IR LED is determined solely from electrical observations.

Lab Weighting: 1.0
Lab on week 5 (2014/09/xx)
PRELAB due on entry to lab period (week 6 starting 2013/09/30)

Condensed Lab Report due on week 6 (2014/10/xx)

Laser Labs and Assignments:

Lab 3: HeNe Lasers


Basic electronics and laboratory skills will be developed while investigating the operation of the helium-neon gas laser. Students will wire a 'bare' gas laser tube to a power supply. As part of an assignment, optical and electrical characteristics will be investigated and students will be introduced to application of the gain threshold equation.

Lab Weighting: 2.0
Lab on week 6 and 7 (2014/10/xx and 2014/10/xx)
PRELAB due on entry to first lab period (week 9 starting 2014/10/xx)

Condensed Lab Report due on week 11 (2014/11/xx)

Week 8: 2014/10/xx
No Labs or classes will be held this week due to reading week. Regular classes and labs will resume on week 9 (starting on 2014/10/xx).

Lab 4: Gas Laser Optics


A bare helium-neon gas laser tube with completely external optics (the tube features windows instead of integral optics like most tubes) will be setup and the mechanics of this laser will be studied. The student will build the entire optical resonator on an optical breadboard and align cavity optics. Various electromagnetic modes (TEMxx) will be observed when aligning the optics. Next, gain will be determined (in the same manner as outlined in chapter 4 of FLL and chapter 2 of LM) by inserting a glass slide intra-cavity at various angles. This glass slide will render a loss ranging from close to 0% at Brewster's angle (polarized) to 8% at perpendicular. Using a reformulated gain threshold equation, actual small-signal gain (g0) for the amplification medium will be determined.

Lab Weighting: 2.0
Part A on week 9 (2014/11/xx)
Part B on week 10 (2014/11/xx)
Part C on week 11 (2014/11/xx)
PRELAB due on entry to the second lab period (week 10 starting 2014/11/xx)

Full Lab Report due at the beginning of your regular lab period on week 12 (2014/12/xx)

Example Lab 5 Marking Scheme example

Lab 5: Lasing Threshold of a Semiconductor Laser


In the lab, several key physical parameters of a commercial-grade semiconductor diode laser are determined and from these a model is developed to predict the threshold current of the device (following example 2.11 in Laser Modeling by Csele). A mathematical simulation of the diode (using the pass-by-pass model) will also be built allowing prediction of key operational parameters of the device.

Lab Weighting: 2.0
Lab on week 12 (2014/11/xx)

Full Lab Report due at the beginning of your regular lab period on week 13 (2014/12/xx)

Contacts:

For the Advanced Lasers program ...
Program Coordinator Alexander McGlashan
Office: S106
Telephone (905) 735-2211 x.7513
E-Mail:

For this specific course ...
Professor Mark Csele
Office: V13A (Office hours are POSTED on the Electroluminescent panel on the office door)
Telephone: (905) 735-2211 x.7629
E-Mail: (Be sure to include 'Lasers' in the subject line to avoid deletion by an anti-spam filter)

URL: http://technology.niagarac.on.ca/staff/mcsele

You are visitor # since June 2009
Copyright (C) Professor M. Csele and Niagara College, Canada, 2002-2014
This course is part of the TECHNOLOGY division

Some images and text excerpted from Fundamentals of Light Sources and Lasers by Csele, John Wiley & Sons, 2004, ISBN 0-471-47660-9 and hence are Copyright John Wiley and Sons. Some images and text excerpted from Laser Modeling: A Numerical Approach with Algebra and Calculus by Csele, CRC Press, 2014, ISBN 9781466582507. Further reproduction in any form is prohibited without written approval from the publishers.