PHTN1306: Lasers III
In this course, students will mathematically model DPSS laser systems and processes with an emphasis of application of models to real-world lasers. Beginning with a pass-by-pass model, several approaches will be taken to improve accuracy when applied to high-gain lasers including the treatment of laser amplifiers as multiple segments. The "gold standard" Rigrod model will be developed and introduced then adapted to handle real losses.
The effects of temperature on both diode and solid-state media will be investigated and application made to the design of DPSS systems (a convolution model being used to predict the effects of diode temperature drift on ultimate output power of the system). As well, thermalization of the LLL of quasi-three-level media will be investigated as re-absorption loss is considered (including such effects as Stark splitting of the LLL which occurs in most real solid-state media). Implications to laser design (e.g. end-pumping) will then be considered. Finally, other thermal effects such as phase-matching of SHGs will be examined and complete optimization of DPSS lasers will be considered.
Many models will use numerical methods and will utilize spreadsheets. The goal is application of theoretical models to real lasers and so a substantial lab component allows students can examine application of, and prove, various models developed in the course on a variety of lasers.
It is required that you have obtained credit in PHTN1400 Principles of Laser Systems to enter this course. A mark of over 70% is highly recommended in the prerequisite course. Due to the mathematical rigor of this course, a strong understanding of mathematics is required for success in this course since both algebra and calculus are used extensively.
This course is offered as part of the Photonics Engineering Technology (3 year) Program at Niagara College.
Two midterm examinations, totalling 60%, as follows ...
Term test #1 on Tuesday 2019/10/29 in class
Involves a mathematical simulation of a laser process as well as theory in the first part of the course including the EDFL, use of dB units, the Rigrod approach (with application to real lasers), Minimum pump power calculations, Stark splitting and diode characteristics and parameters.
Term test #2 on Tuesday 2019/12/10 in class
Covers models for predicting optimal output.
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:
- 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 - those qualifying for an SE must apply to the chair who will arrange for the SE (since staff must be assigned to deliver the SE). Attendance and lab performance will be considered.
- 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.
Laser Modeling: A Numerical Approach with Algebra and Calculus by Csele, 2014, CRC Press, ISBN 9781466582507
The text, and the models presented within it, will be used extensively in this course including the Pass-by-pass model (chapter 3), Rigrod approach (chapter 4), Quasi-three-level lasers and Stark splitting (chapter 5), and Convolution model (chapter 5).
Course Notes and References
There are several labs and assignments in this course. Lab sessions are two-hours in length.
In line with departmental policies, the lab/assignment 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.
Assignment 1: Pass-by-pass Model
Models from the text are applied to a high-gain laser.
Assignment due at the beginning of the lecture period (Tuesday 2019/09/24). Failure to submit this assignment 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 or assignment results in immediate EXPULSION from the course without recourse).
Lab 0: Tutorial
In this tutorial the following topics will be reviewed:
Lab (for all groups) on week 2 (On 2019/09/09) in V115
- A review of the use of dB and dBm units
- The use of attenuators
- Noise and signal
- How gain (g0) is determined in this amplifier
- How saturation gain and saturation power is determined in this amplifier
Lab 1: Modeling a Fiber Laser
In this lab, key parameters of an Erbium-Doped Fiber Laser (EDFL) will be determined in the lab including the loss of system elements and saturation parameters of the amplifier. Determined parameters will then be applied to predict laser performance using several models including the Rigrod model. Included in the lab is a review of OSA usage, gain determination, and use of dBm and linear units.
Labs for group A on week 3 (On Mon 2019/09/16)
Labs for group B on week 4 (On Mon 2019/09/23)
Lab Report due for BOTH groups at the beginning of the lecture period on Tuesday 2019/10/01. 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).
Lab 2: Re-Absorption Loss in a DPSS System
Re-absorption loss of the 946nm quasi-three-level transitions in Nd:YAG will be accurately computed and applied to predictions of output pump power for a commercial laser based on the temperature of the amplifier. Specific attention will be paid to Stark levels, and saturation effects of the LLL thermal population will be examined.
Labs for group A on week 6 (On 2019/10/07) at 12:30 and for group B on week 6 (On 2019/10/07) at 1:30.
PRELAB (worth 25%) due on entry to the lab period
Lab Report due for BOTH groups at the beginning of the lecture period on Tuesday 2019/10/15. 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).
Lab 3: Predicting Pump Absorption using the Convolution Technique
In this lab, you will measure parameters of a typical laser pump diode including the output spectrum, and wavelength temperature coefficient. Gain of the amplifier, which is a function of the actual absorption of pump radiation, is calculated using the convolution technique using the observed pump spectrum and the wavelength coefficient of temperature. This will allow the determination of the effect of temperature drift on the output of a DPSS laser.
Labs for group A on week 10 (On 2019/11/04) and for group B on week 11 (On 2019/11/11).
Lab Report due for BOTH groups at the beginning of the lecture period on Tuesday 2019/11/19. 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).
Assignment 2: Complete DPSS Model
Models from the year are combined to predict the output of a DPSS laser based on temperature.
Assignment due at the beginning of the lecture period (Tuesday 2019/12/03). Failure to submit this assignment 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 or assignment results in immediate EXPULSION from the course without recourse).
For the Photonics Technician/Technology programs ...
Program Coordinator Alexander McGlashan
Telephone (905) 735-2211 x.7513
For this specific course ...
Professor Mark Csele
Office: V113E (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)
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Copyright (C) Professor M. Csele and Niagara College, Canada, 2017-2019
This course is part of the
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 publisher.