technology > courses > PHTN1400

Course Info | Course Policies | Evaluation / Check Marks | Class Notes | Labs |

Course Description

The output of our Innova-90 argon laser is seen here. Using multi-line optics several wavelengths lase simultaneously. The output beam is then split by a diffraction grating to reveal all the spectral components. As tube current is increased gradually more lines begin to appear - in this case the current is relatively low (< 20A) so only five lines are lasing. Clearly visible are the 488nm blue and 514nm green lines. This laser is used to demonstrate Mode structures (TEM_xx), wavelength selection, quantum principles (such as competition for energy levels), and ion laser hardware (e.g. power supplies and tube design). In multi-line, multi-mode operation it can produce seven watts of blue-green laser light.

A detailed description of the course can be found in the Course Outline (CO) and Teaching & Learning Plan (TLP) documents which can be found on Blackboard (for registered users only). The TLP contains a list of all topics covered.

This course is offered as part of the Photonics Engineering Technician (2 year) and Technology (3 year) Programs at Niagara College.

Evaluation ...

Textbook

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

Chapters 6 through 15 are covered in this course.

Supplemental Text: The Laser Guidebook, 2nd edition (or newer) by Hecht, McGraw-Hill, 1992, ISBN 0-8306-4274-9

For specific elements of this course, refer to both the Course Outline (CO) and the Teaching & Learning Plan (TL&P) documents, both available on Blackboard.

Students will use a Crystal Technologies AO Modulator in the laboratory to examine both Bragg and Raman-Nath regimes. Here a HeNe beam is diffracted by the modulator.

Course Notes

Pre-lab Material ...

• Standard Operating Procedures (SOPs) for lasers in Niagara College's high powered laser labs.
• Laser Safety For Students from the in-class presentation.
• Coherent.Com where you may download the laser safety video shown in class. Also, some manuals for our Coherent lasers are available here.
Watching this video, and writing a quiz BEFORE the first lab is MANDATORY!

CW Gas Lasers ...

• Entrance Exam Solution useful for identifying areas requiring academic attention. (The examination was given last term).
• Helium-Neon Lasers from the in-class presentation. Covers HeNe lasers and wavelength selection via optics.
• HeNe Gas Laser - Case Study outlining issues such as competition for ULL (good prep for the term test).
• Ion Lasers from the in-class presentation. Covers Ion lasers as well as longitudinal modes, linewidth, and use of etalons.
• Ion Lasers - A Summary from a Spectra-Physics manual. A good overall review of ion lasers.
• A few links for the unit on ION LASERS:
  • History of Gas Lasers from Optics & Photonics News published by the OSA (must be opened from a college computer).
  • Sam's Laser FAQ on Ion Lasers including discussions of gas pressure issues ("spectral balance") in Ar⁺ and Kr⁺ lasers
• CO2 Lasers - Low Pressure primarily covering quantum mechanisms of the CO2 laser as well as design of CW lasers.
• A few links for the unit on CO2 LASERS:
  • Sam's Laser FAQ on Homebuilt CO2 Lasers including discussions on optics

Pulsed Gas Lasers ...

• E/P Ratio covering design issues with nitrogen, excimer, and CO₂ gas lasers.
• E/P Graph allowing determination of the E/P ratio for nitrogen gas.
• Pulsed Gas Lasers covering E/P issues, preionization, and discharge circuit design for TEA, Excimer, and N₂ lasers.

Solid-State Lasers and Q-Switching...

• Solid State Lasers from the in-class presentation. (Password protected PDF). REVISED for 2013
• A Review of Pre-Requisite Material from PHTN1300 for Solid-State Lasers, Q-Switching, and Term Test #2 ...
  • Laser Gain from the in-class presentation (the most important concept from last term!) (Password-protected PDF). Contains an example question about Q-Switch holdoff which is an excellent introduction to Q-Switching.
  • Cross-Sections and Gain from the in-class presentation (the second most important concept from last term!) (Password-protected PDF). Contains an example question pertaining to computation of inversions and thermalization of the LLL.
  • Thermal Populations and Gain (Password-protected PDF). A complete example on computing thermalization of the LLL and gain. Excellent study material for TERM TEST #2.
• Q-Switching (Password protected PDF)
• Harmonic Generation Password protected PDF file.
• Dye Lasers Password protected PDF file.

• Notes on Lab Reports a tutorial on writing formal lab reports.
• Notes on Lab Reports, Part 2 a tutorial on writing condensed lab reports.
• Midterm #1 Preparation Questions a selection of example questions from previous midterm examinations as covered in class (solutions done in review class). Password protected PDF file.
• Term Test #1 Formula Sheet.
• Midterm #1 SOLUTION.
• Midterm #2 Preparation Questions a selection of example questions from previous midterm examinations as covered in class (solutions done in review class). Password protected PDF file.
• Term Test #3 Review Questions from previous tests and class presentations.
• Formula Sheet a typical formula sheet from a previous exam.
• Midterm #3 Formula Sheet from 2012.

• September 1964 How a Persevering Amateur Can Build a Gas Laser in the Home (HeNe Laser)
• December 1965 Deep Sky Photographs with a 35-Millimeter Camera and More about the Homemade Laser (Follow-Up to the above article)
• October 1980 A Homemade Mercury-Vapor Ion Laser That Emits Both Green and Red-Orange (Hg⁺ Laser)
• Feburary 1969 How to Construct an Argon Gas Laser with Outputs At Several Wavelengths (Ar⁺ Laser)
• June 1974 An Unusual Kind of Gas Laser That Puts Out Pulses in the Ultraviolet (N₂ Laser)
• Feb 1970 A Tunable Laser Using Organic Dye Is Made At Home for Less Than $75

Laboratory Assignments

Students in 2013W will complete five laboratory assignments, each two-weeks in length. Lab sections are split into smaller groups (A and B) which perform different parts of the lab alternatively.

NOTE: You will NOT be permitted into the lab and will be marked absent unless the safety quiz on Blackboard has been successfully completed by the day before the beginning of the first lab

Lab #1: Safe Operation of Lasers
The safe operation of lasers is examined including use of high-powered ion lasers. In the lab, the concept of Nominal Hazard Zone (NHZ) and optical density (OD) will examined with respect to correctly choosing safety glasses for specific lasers. The operating procedures of large ion lasers will also be demonstrated including use of current and light regulation modes, optics changes, and procedures to maintain a laser such as this.
WARNING:
  Safety Quiz on BLACKBOARD is due by Monday 2013/01/21 BEFORE admission to this lab. NO EXCEPTIONS: NO SUCCESSFUL QUIZ, NO LAB ADMISSION (And a mark of ZERO will result)
Lab Sessions:
  Group A - Part A on 2013/01/24, Part B on 2013/01/31
  Group B - Part B on 2013/01/24, Part A on 2013/01/31
  All Sections DUE on 2013/02/07 (at the beginning of the lab period)


Lab #2: Cavity Alignment
Complete alignment of the optics of two types of lasers will be completed. First, the optics on a large-bore MPB IN-100 carbon-dioxide laser will be aligned using a coaxial HeNe laser beam. Burn patterns will then be used to analyze beam structure under optimized and non-optimal conditions. Next, the optics (HR, OC, and Fold Mirrors) on a Coherent argon-ion laser-pumped dye laser will be removed and aligned by using the fluorescence of the dye itself to provide alignment 'spots'. A lab report will outline details of the procedure.
Lab Sessions:
  Group A - Part A on 2013/02/07, Part B on 2013/02/14
  Group B - Part B on 2013/02/07, Part A on 2013/02/14
  All Sections DUE on 2013/02/21 (at the beginning of the lab period)


Lab #3: Pulsed Gas Lasers
Students will mix various gas fills for a Lumonics Excimer 500 and a Lumonics TEA-203 CO₂ laser in V15 and will study the effect on power output. In the excimer laser, a Helium-Nitrogen mixture will be employed with various concentrations of nitrogen (the active lasing species) and the effect of nitrogen concentration on output power noted. In the TEA laser pressure and voltage will be varied. Results will be correlated with the calculated E/P ratio of the gases employed.
Lab Sessions:
  Group A - Part A on 2013/02/21, Part B on 2013/03/07
  Group B - Part B on 2013/02/21, Part A on 2013/03/07
  All Sections DUE on 2013/03/14 (at the beginning of the lab period)


No Labs on the Week of March Break

Lab #4: DPSS Lasers NEW for 2013
A complete overview of DPSS design concepts including the characteristics of pump diodes, absorption characteristics of vanadate (Nd:YVO₄), and temperature sensitivity of harmonic generators (phase-matching).
Lab Weight:
This lab is weighted heavier (1.5 times) than the other labs in this course
Pre Lab:
A prelab is due upon entering the lab for the first of the two lab sessions. This prelab is worth 10% of the lab and will receive a mark of ZERO if not produced immediately upon entry to the lab. The prelab involves significant reading and calculations - start it early.
Lab Sessions:
  Group A - Part A on 2013/03/14, Part B on 2013/03/21
  Group B - Part B on 2013/03/14, Part A on 2013/03/21
  All Sections DUE on 2013/03/28 (at the beginning of the lab period)


Lab #5: Q-Switched Lasers
A Diode-Pumped Lee YAG Laser employing an AO Q-switch will be examined with the effect of pulse rate on output determined. In order to demonstrate how an AOM works and ways in which it may be used an external AOM will be aligned for Bragg diffraction, with the effective intra-cavity loss determined, and an AOM modified for use as a PCAOM will be used to separate the multiple wavelength (RGB) output of a 'white light' HeCd laser.
Lab Weight:
This lab is weighted heavier (1.5 times) than the other labs in this course
Pre Lab:
A prelab is due upon entering the lab for the first of the two lab sessions. This prelab is worth 10% of the lab and will receive a mark of ZERO if not produced immediately upon entry to the lab. The prelab involves significant reading and calculations - start it early.
Lab Sessions:
  Group A - Part A on 2013/03/28, Part B on 2013/04/04
  Group B - Part B on 2013/03/28, Part A on 2013/04/04
  All Sections DUE on 2013/04/11 (at the beginning of the lab period)


The lab schedule is subject to change based on availability of laboratory equipment

Contacts:

For the Photonics Technician/Technology programs ...
Program Coordinator Alexander McGlashan
Telephone (905) 735-2211 x.7513
E-Mail:

Copyright (C) Mark Csele and Niagara College, Canada, 2005-2013
Some images and text are published in Fundamentals of Light Sources and Lasers by Csele, Wiley (2004), ISBN 0-471-47660-9 and hence are Copyright (C) John Wiley and Sons. Further reproduction in any form is prohibited without written approval from the publisher.

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