PHTN1300:Principles of Light Sources and Lasers
This course is dedicated to the fundamental operating principles of lasers including the quantum processes involved (with basic rate equations), the concept of laser gain and loss, excitation (pump) mechanisms, and optical resonators. Emphasis will be placed on formulation and use of the threshold gain equation, including situations with intra-cavity losses. An intensive laboratory component allows students to explore course material in a practical hands-on manner. This course has been updated for fall of 2016 to reflect the new "Photonics 2.0" curriculum - a fundamental understanding of quantum mechanics is required as a prerequisite.
Prerequisites for this course include PHYS1215 Light and Spectroscopy and MATH1231 Mathematics II. Both are required for entry to this course.
This course is a prerequisite for
PHTN1432. 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.
Three midterm examinations, totalling 50%, as follows ...
These midterm tests primarily evaluate fundamental concepts of light emission and lasers. (e.g. expect questions of the nature "solve for xxxx given parameters yyyy"). Questions pertaining to knowledge gained during lab assignments will also be incorporated into the tests (e.g. calculating wavelengths using a spectroscope, calculating energies of levels and transitions, etc).
Midterm #1 in class on MONDAY 2016/10/17 (Moved due to Thanksgiving holiday)
One Hour, in class, worth 12.5%. Covering some review material (atomic emission, spectroscopy, Chapters 1, 2, and 3 of FLL) as well as semiconductors and thermal energy (e.g. junction temperature and bandgap/peak wavelength calculations from lab 1), and basic laser concepts of gain and loss (including formulating a threshold gain equation and numerical solutions)
Review held in class prior to the test
Midterm #2 in class on MONDAY 2016/11/14
One Hour, in class, worth 12.5%. Covering semiconductor lasers, two-slope threshold analysis method (from lab 2), characteristic temperature calculations and usage (from lab #2) and especially the gain threshold equation (from lab 3, Chapter 4 of FLL, and Chapter 2 of LM both of which are required reading) and application to various laser configurations.
Review held in class prior to the test
Midterm #3 in class during week 15 (TUESDAY 2016/12/13)
Two hours, in class, worth 25%. 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)
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.
Reviews will be held in class during the week prior to the test, including a look at last year's test.
Labs and assignments combined for a total of 50%
Course Policies ...
Course policies follow the Standardized Policies and Procedures for CEE (dated January 2011). In summary:
- LATE assignments are worth ZERO. There is no "grace period" with a "per day" penalty. Late submissions (i.e. ANY not printed and ready when you enter the lab) receive a mark of zero. You will be DENIED access to the printer at the start of the lab - either the lab is ready to submit, or it is late and hence worth zero.
- Students are allowed only ONE single-day late submission without penalty. This is a once only one-day extension ... once used, any further late submission will receive an automatic zero.
(This policy reflects expectations in the real world: to be late for work, once, will likely not result in termination however chronic late arrivals will almost certainly result in job loss. Develop good work ethic _now_.)
- Students must pass the theory (testing) and practical (lab/assignment) portions of the course separately in order to receive a passing grade. If a failing grade is received in either portion, then the lower of the two marks (theory or practical) will become the final grade.
- In order to be considered for supplementary evaluation (SE) upon failure in this course, a mark of 50% minimum will be required in the practical (lab/assignment) portion of the course plus a mark of 45% minimum in the theory (testing) portion. A theory mark of 44% or less, or a lab mark of 49% or less, will result in failure with no SE option.
- Granting of an SE is not automatic nor it is a right - it is a special consideration granted by the associate dean and those qualifying for an SE must apply to the associate dean who will arrange for the SE (since staff must be assigned to deliver the SE). Consideration will be made based on individual circumstances and attendance will be considered.
(Don't expect the associate dean's office to grant you a "second chance" if you haven't done ALL you can to learn the material including attending lectures and completing homework assignments. Attendance will be taken at random times during the term.).
- Devices capable of RF reception are specifically banned during all examinations and tests. This includes cell phones (which are not permitted, whether turned on or not) as well as tablets and laptops. Scientific calculators must not have RF capability (i.e. the use of a cell phone, tablet, or laptop as a calculator is expressly forbidden even if the "wireless" function is switched off). Translational references and dictionaries must be in paper form, not on an electronic device.
Complete course policies can be found in the Teaching and Learning Plan (T&LP) document found on Blackboard.
There are two textbooks in this course. These same texts will be used next term in PHTN1400 and in the third year in PHTN1500 (i.e. you will not have to purchase another text for those two courses).
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.
ERRATA: In Fundamentals, Snell's law (equation 4.9.3 and in example 4.9.2) has the index of refraction values reversed. Also, in example 4.9.2 an index of refraction of 1.44 was assumed.
Laser Modeling: A Numerical Approach with Algebra and Calculus by Csele, 2014, CRC Press, ISBN 9781466582507
Chapters 1 to 3 are covered in this course. Of special interest is chapter 2 which outlines the formulation of the gain threshold equation in great detail and chapter 3 which presents gain saturation and application to modeling a basic laser with respect to output power and other key parameters. Other parts of the text will be used extensively in subsequent terms.
ERRATA: In Laser Modeling, in unity-gain equations (2.1), (2.6), and (2.8) the correct terms are egx not e-gx. Gain is always a positive quantity, attenuation is negative. Also, in table 8.1 (pp.222), an ULL lifetime of 29.9ns should be used for calculations of saturation intensity (see example 3.1 on pp. 72 for an explanation).
Course Notes and Links
NIST eBook of Atomic Spectral Data as required for several labs in this course
Notes On Lab Reports details what is required for a lab reports in this course and a complete tutorial on writing a formal lab report with an example.
Using a Spectroscope the basic theory and use of the spectroscopes
in lab 1
Spectroscopes a reference on using a spectroscope as required for Lab 2 (Password-protected PDF)
Lecture Notes: First Third of the Course
Chapter 1 and 2 notes on Blackbody radiation and atomic emission (Password-protected PDF)
Chapter 3 - Quantum Intro notes on introductory quantum mechanics concepts (Password-protected PDF)
Laser: Basic Concepts from the in-class presentation (Password-protected PDF)
Laser Gain from the in-class presentation (the most important concept of the entire year!) (Password-protected PDF)
Practice Questions a collection of practice questions (with answers, but not full solutions) on basic concepts. Provides an excellent self-assessment. (Password-protected PDF)
Formula Sheet for the above questions (PDF)
Lecture Notes: Second Third of the Course
Cavity Losses from the in-class presentation describing how to handle both point and distributed losses. Required for lab #4 (to handle the loss of the inserted window). First, see examples 2.3 and 2.9 in Laser Modeling by Csele. Contains good examples for study purposes (Password-protected PDF)
Pre-Lab #4 Notes an overview of concepts required for the lab ... read this BEFORE Lab #4. Also contains a good example for study purposes (Password-protected PDF)
HeNe Visible Gas Laser the development of the visible HeNe laser from the OSA www.osa.org to which all student have access from any college computer. Read this for HOMEWORK as it makes an excellent review after lab #3 of major concepts! Note the comments on p.37 regarding the intensity of the 632.8nm line - sound familiar? (Password-protected PDF)
Midterm #2 Preview a collection of practice questions (with answers, but not full solutions) (Password-protected PDF)
POST Midterm #2 Notes a few solutions to 2014F midterm questions with explicit mathematical steps required (Password-protected PDF)
Lecture Notes: Final Third of the Course
Saturated Gain from the in-class presentation and the second most important concept of the entire year! Covers calculation of saturation intensity/power and use of the gain saturation formula to compute output power for a laser. (Password-protected PDF)
Cross-Sections and Gain from the in-class presentation. Covers level lifetime and CW lasing, calculating required inversion, and calculation of thermal re-absorption loss. (Password-protected PDF)
Test #3 Review (in class):
- Test #3 Material - a list of topics covered on the third and final test.
Helium-Cadmium Example from the in-class presentation. A complete example of the kind you'd see on the test which will be solved in it's entirety in class. Numerical answers are provided on the last page, complete solutions will be done in lecture only on request. (Password-protected PDF)
Thermal / Gain Example a second study example based on a carbon-dioxide laser which will, again, be solved in class upon request. (Password-protected PDF)
Test #3 Review (homework):
- Example Exam a few practice questions in the exact same form as you'd find on a test (covering most concepts except for Fresnel equations). Complete solutions are provided in detail. (Password-protected PDF)
- Formula Sheet from Test #3
- Example Exam #2 a complete test #3 in the exact same form as you'd find on a test (using questions from previous tests). Numerical solutions may be found on the last page but not complete solutions ... consider this one a real test of your knowledge (and questions in the form of "How do I solve ..." will not be entertained as all are similar to questions you've already seen in the lectures). (Password-protected PDF)
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.
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 2016/09/12)
As with all labs, attendance is mandatory (See T&LP for details as covered in the first class). Failure to attend this lab will result in being placed on course condition which will result, on the next absence, in automatic expulsion from the course.
Lab 1: Determining Planck's Constant
An expanded version of a lab you performed last year emphasizing data analysis using linear regression, estimation of error tolerances, and compensation for thermal energy. 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
Part A on week 3 (starting 2016/09/19); Part B (completion) on week 4 (starting 2016/09/26) - this lab is two weeks in length
PRELAB due on entry to first lab period (week 3 starting 2016/09/19). Prelabs are not accepted late: they are either received upon entry to the lab or are assessed a mark of zero without exception.
Condensed Lab Report due on week 5 (2016/10/03)
Lab 2: Laser Diodes
The optical and electrical characteristics of visible red laser diodes is investigated. By using a Peltier effect thermoelectric cooler the effect of temperature on these devices is investigated.
Lab Weighting: 1.0
Lab on week 5 (starting 2016/10/03)
Condensed Lab Report due on week 6 (2016/10/10)
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 (2016/10/10 and 2016/10/17)
PRELAB due on entry to first lab period (week 6 starting 2016/10/10)
Condensed Lab Report due on week 9 (2016/10/31) after the break
Week 8: 2016/10/24
No Labs or classes will be held this week due to reading week. Regular classes and labs will resume on week 9 (starting on 2016/10/31).
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: 3.0
Part A on week 9 (2016/10/31)
Part B on week 10 (2016/11/07) - prelab due on this lab period
Part C on week 11 (2016/11/14)
PRELAB due on entry to the second lab period (week 10 starting 2016/11/07)
Full Lab Report due at the beginning of your regular lab period on week 12 (2016/11/21)
Example Lab 4 Marking Scheme example
Lab 5: DPSS Lasers
The minimum pump power of a Diode-Pumped Solid-State (DPSS) laser will be computed theoretically from relations in the Laser Modeling
text and compared to experimental measurements from the lab. Also covered is the appplication of the saturated gain formula in predicting output power.
Lab Weighting: 1.0
Lab on week 12 (2016/11/21)
PRELAB due on entry to first lab period (week 12 starting 2016/11/21)
Condensed Labb Report due at the beginning of your regular lab period on week 13 (2016/11/28)
For the Photonics Technician/Technology programs ...
Program Coordinator Alexander McGlashan
Telephone (905) 735-2211 x.7513
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)
You are visitor # since May, 2003
Copyright (C) Professor M. Csele and Niagara College, Canada, 2002-2016
This course is part of the
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.