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Course Info | Class Notes | Evaluation / Check Marks | Labs | Class Schedule & Homework |

Course Description

PHTN1300 Principles of Lasers & Light Sources

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Evaluation ...

One midterm test valued at 20% each
MIDTERM:
• Gas Physics including use of gas laws, use of throughput/speed calculations
• Vacuum Technology including gauges (principles of operation, characteristics, limitations) and pumps (principles, characteristics, limits)
• Interpreting and using Mass Spectrometers
• System operation procedures (use of pumps, valves, and gauges in a system)
• All material from labs 1 through 3
One final exam valued at 40% each


Check your Registration Status, Marks, and Lab Group Assignments here

The Physics of Gases and Vacuum Systems

* The fundamental nature of gases and gas flow
* Gas Laws (e.g. Boyles Law) and applications
* The concept of vapour pressure and how it applies to gases, liquids, and solids
* The concept of conductance in a vacuum system
* Why a high vacuum is required (i.e. Mean Free Path)
* Purity in vacuum systems (including residual gas analysis)

* Operational principles of various mechanical pumps as well as limitations
* Operation of high vacuum pumps such as oil diffusion pumps
* Backstreaming and cryotrapping of diffusion pumps
* Principles of UHV pumps such as ion and getter pumps
* Measuring vacuum pressures using various gauges (e.g. pirani, ion, etc.)
* Leak detection and RGA
* Design and operation of a practical vacuum system
* Construction of vacuum systems including materials and couplings
* Identify sources of contamination and leaks in a typical vacuum system

* Evaporation Techniques (filaments, baskets, and boats)
* E-Beam Techniques and applications to optical materials
* Sputtering Techniques
* Calculating thickness using Point-Source Load Calculations from Nomograph
* Crystal Thickness Monitoring (In-Process)
* Operating a vacuum coating system

* Materials available for optics (reflectors, dielectrics)
* Physics of optics (e.g. principle of interference)
* Design of antireflective coatings
* Design of dielectric filters and mirrors

Class Schedule & Homework

Week #1 (2010/01/11):
  Introduction
  Fundamental vacuum concepts
  Pressure, units of measurements
  Gas Laws
  In-class example: load-lock chamber pressures
  Homework for next week: Read Chapter 1 of the Varian Book
                          Read pp.198 on Turbomolecular pumping systems
Week #2 (2010/01/18):
  Partial and vapour pressures
  Gas flow
  Mean free path
  Conductance
  Gauges
  Homework for next week: Read Chapter 5 of the Varian Book
Week #3 (2010/01/25):
  Gauges (roughing and high vac)
  Mass spectrometers
  Homework for next week: Read Lesker notes on RGAs
                          Read Chapter 2 of the Varian Book
Week #4 (2010/02/01):
  Mass spectrometers, leak detection
  Vacuum pumps (roughing, diffusion pump)
  Homework for next week: Read Chapter 3 of the Varian Book
Week #5 (2010/02/08):
  Diffusion Pumps
  Calculating Q of fore and diffusion pumps - crossover pressures
  Oils, cold traps
Week #6 (2010/02/15):
  Turbomolecular Pumps
  Cryopumps
  UHV pumps
Week #7 (2010/02/22):
  Vacuum system design, materials
  Leak testing methods

Laboratory work is a vital portion of this course. Whether experiencing first-hand the difficulties encountered while depositing thin films in a high-vacuum evaporator in the cleanroom (for example, controlling deposition rates manually on a thermal source and producing an accurate deposit thickness) or simply observing how an auto-ranging vacuum gauge operates in the spectroscopy lab, laboratory work provides hands-on skills not obtained from classroom work alone. Niagara is proud to have two unique dedicated lab spaces: the spectroscopy lab in V12 and the class-1000 cleanroom in V13C, both of which are utilized in this course.

Unless noted otherwise, all labs are due one week after the work is completed in the laboratory by or at the time of the beginning of the lab period, after which they are considered late and penalized at the rate of 10% per day (i.e. the 'day' late begins at the beginning of the lab period).

Lab1 - Gas Discharge Tubes
Using a turbomolecular high-vacuum system gas discharge tubes will be pumped. The effects of gas pressure on the discharge will be observed and the effect of impurities on the line spectrum of a discharge will be examined.
Labs: Group A week of 2010/01/18, Group B week of 2010/01/25
Due: in one week (at the beginning of lab period - Group A week of 2010/01/25, Group B week of 2010/02/01)
Sample Lab1 Marking Scheme as a PDF document. Marks are assigned to items identified in the lab outline as 'required' (refer to the lab outline for details)

Lab 2 - Pressure Measurement
A two week lab in which students alternate parts A and B in two consecutive weeks. Pressure measurement techniques for high-vacuum systems are examined. The performance of various roughing gauges will be investigated for accuracy over a given range and the effect of gas composition on gauge accuracy will be investigated. Residual gas analysis is then performed in which gas samples will be analyzed for isotopic purity using a quadrupole mass spectrometer - in addition to pure gases such as neon and carbon dioxide, air will be analyzed.
Lab: Group A Part A Week of 2010/02/01, Part B Week of 2010/02/08, Group B Part A Week of 2010/02/08, Part B Week of 2010/02/01
Due: in one week (at the beginning of lab period - BOTH GROUPS week of 2010/02/15)
Sample Lab2 Marking Scheme as a PDF document. Marks are assigned to each question as shown.

Lab 3 - Gas laser tubes
Students will use a high-vacuum system (including turbomolecular pump and RGA) to evacuate and reprocess a helium-neon gas laser tube. Processing includes outgassing the tube by thermal and gas flushing methods. Students will be required to adjust pressure of the gas mix used (helium and neon) to optimize laser tube output. Once optimized, the tube will be sealed and monitored for long-term stability (i.e. the effects of residual gases in the tube such as trapped oxygen will be observed). Residual gas analysis will be used to show how gases evolve as the laser operates and E/P calculations will be performed comparing experimental to theoretical ratios for neon. As well, students will repump an argon-ion laser in order to experimentally determine the E/P ratio of argon gas.
Sample Lab3 Marking Scheme as a PDF document. Marks are assigned to each question as shown.

Lab 4 - Basic Thin Film Techniques: Thermal Evaporation Deposition
Students will operate a high-vacuum thermal deposition system to deposit a thin-film of aluminum onto glass substrates. During this lab students will be exposed to the operating principles of high-vacuum systems, practice working in a class-1000 cleanroom environment, gain experience controlling deposition rate by regulating filament current, and utilize in-process quartz crystal thickness monitoring to assure a proper film thickness.
No Lab Report Required - Lab Report will be combined with Lab #5
Labs: ALL Groups together


Lab 5 - Optical Calibration of a Thin-Film monitor
Students will calibrate the tooling factors on a thin-film monitor by using optical means in which basic dielectric filters consisting of a layer of dielectric Na₃AlF₆ sandwiched between two thin layers of aluminum are fabricated. This structure, which resembles a Fabry-Perot interferometer, acts as a high-performance optical filter with a narrow spectral width. Filters will be modelled with thin film software, deposited in the cleanroom using the Bendix thermal evaporator, and filters will be analyzed by a Perkin-Elmer Lambda-3B spectrophotometer (in V12 outside the lab time). By correcting the model in software, the tooling factors for various substrate locations in the chamber will be determined.
Sample Lab 5 Marking Scheme as a PDF document. Print and append as the last page of the lab report.

Lab 6 - Dielectric Mirrors (eBeam Deposition)
Students will design (using FilmStar software) then fabricate a QWOT multilayer dielectric mirror on 'Sparky', a 13kW eBeam deposition system. The resulting coating will be analyzed spectrographically.


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

Course Notes and Links

• The TurboPump System system diagram and instructions for using the turbomolecular pumping facility in V12
  
• The Ocean Optics Spectrometer a brief intro to the spectrometer used in gas discharge experiments in V12.
• NIST eBook of spectral data - Required for many labs in this course.
• Gauges - Supplementary Notes on roughing gauges from class
  
• Ion Gauges
  
• Yeagle Technology Inc includes information on sources and interpreting RGA data (fragmentation)
• Application Notes: Using Q and S applying throughput and speed to a real system (examples)
  
• Notes On Pressure Reduction and gas composition as required for the gas laser reprocessing lab
  
• Kurt J. Lesker Company company site containing tutorials on Vacuum Basics including RGAs (Technical Info -> Vacuum Basics). Specific pages of interest:
• Vacuum Technology Fundamentals basic physics of gases, behaviour of vacuum systems (e.g. outgassing), and an excellent tutorial on how RGAs work and how results are interpreted. Required reading.
• Helix Technologies / CTI Cryogenics Cryopump fundamentals.

• Notes On Loading Source Filaments how to calculate the amount of evaporant required for a particular deposition BEFORE the chamber is pumped down!
  
• Center for Applied Microtechnology at the University of Washington which features a cleanroom like ours. Specific pages of interest:
• Process Tutorials including vacuum systems and cleanroom operations
• CVC Vacuum Evap System standard operating procedures. This machine is similar to our CVC (Bendix) evaporator.
• Society of Vacuum Coaters Specific pages of interest:
• History Of Vacuum Coating a (large) article by Donald Mattox outlining essentially all coating technologies from a historical perspective. Required reading.
• Thin Film Applet allowing the exploration of how an antireflective coating works.
• Melles Griot Optics Guide covering the basics of optical coatings (required reading)
• Optical Structures 1 - Antireflective Coatings
• Optical Structures 2 - MDM Filters
• Optical Structures 3 - V Coatings
• Optical Structures 4 - Dielectric Reflectors
• What Is Sputtering? from AJA International, including animations.
• Ellipsometry Tutorial from J.A. Woolam (manufacturer of spectroscopic ellipsometers)

• Final Review Questions

Lab Equipment used in this course

• The TurboPump System system diagram and instructions for using the turbomolecular pumping facility in V12 used for evacuating and filling gas discharge tubes as well as mass spectroscopy experiments.
• The Ocean Optics Spectrometer a brief intro to the spectrometer used in gas discharge experiments in V12.
• The Bendix High-Vacuum Deposition System details of system components including pumps, gauges, and valves. See also the page from U.Washington above which features operating procedures.
• Branson/IPC Plasma Cleaner used to clean substrated prior to deposition
• The Alcatel TurboPump System system diagram and instructions for using the second turbomolecular pumping facility in V12 used for research and projects.
• Edwards high-vacuum deposition system including gauges, thickness monitor, and source filaments
• Rudolph FTM a film thickness monitor or ellipsometer used to measure actual film thickness by optical means. In our lab, used as a calibration check for crystal monitors. For details on how it works, search the Lesker site for 'ellipsometer' under 'process instruments' notes.

Contacts:

For this course ...
Professor Mark Csele
Office: L-17 (Office hours are POSTED on the EL panel on the door)
Telephone: (905) 735-2211 x.7629
E-Mail: (Be sure to include 'PHTN1432' in the subject line to avoid deletion by an anti-spam filter)
URL: http://technology.niagarac.on.ca/people/mcsele

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