1 / 11

[5] Investigations into Laser Diode (LD) Self-Mixing

Joint QUASAR and THz Group Workshop on Accelerator Science and Technology GSI: Seminar Room Theory Group: 10:30 - 10:40. [5] Investigations into Laser Diode (LD) Self-Mixing. by Nicola Swindells (QUASAR Group, Cockcroft Institute). Contents. Introduction:

sandersf
Download Presentation

[5] Investigations into Laser Diode (LD) Self-Mixing

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Joint QUASAR and THz Group Workshop on Accelerator Science and Technology GSI: Seminar Room Theory Group: 10:30 - 10:40 [5] Investigations into Laser Diode (LD) Self-Mixing by Nicola Swindells (QUASAR Group, Cockcroft Institute) Nicola Swindells

  2. Contents • Introduction: • What Laser Diode (LD) Self-mixing involves • What we hope to achieve with LD Self-Mixing • The experiment so far: • Challenges and how they were overcome • The current status of the project with Preliminary results • The Importance of Lens Configurations • The next stage in the project Nicola Swindells

  3. Introduction to LD Self-Mixing • Laser diode produces the beam • Photo diode measures flux • Self-aligning detection method, more compact than interferometry • Can be used to measure the velocity of moving targets. Nicola Swindells

  4. QUASAR Group Aspirations forSelf-Mixing Applications • Use within cooled vacuum storage rings • Measuring the velocity of gases • Determining self-mixing signal variations due to external radiation acting upon beams inside fibres Nicola Swindells

  5. Experimental Setup LASER Diode DC motor for the moving stage PI Moving Stage: M403.4VP LASER Controller Mirror Mercury C863 Controller for the moving stage Oscilloscope Trans-Impedance Amplifier Nicola Swindells

  6. Challenges Encountered during the Project 0-30mm 30-100mm Nicola Swindells

  7. Current Status • Red LASER Diode • Preliminary signals (below) • Temperature causing an overload? • Diffusive targets also produce signals Nicola Swindells

  8. Importance of the Lens Configuration • Collimated beams • Diverging beams • Converging beams Nicola Swindells

  9. The Next Steps to be Taken • Change the beam from converging to diverging • Create more feedback in the signal • Build the adapter plate to allow more flexible target mounting Nicola Swindells

  10. Summary • More compact than interferometry • Overcomes difficulties in distance and velocity measurements • Opt for diverging beams • Works for reflecting and rough surfaces • Ensure the correct equipment is to hand! Nicola Swindells

  11. References • Giuliani et al. (2002) Laser diode self-mixing technique for sensing applications • Scalise, Steenbergen & de Mul (2001) Self-mixing feedback in a laser diode for intra-arterial optical blood velocimetry • Lang & Kobayashi (1980) External Optical Feedback Effects on Semiconductor Injection Laser Properties • Wei et al. (2007) Transition Analysis for Moderate Feedback Self-Mixing Interferometry • Rabal &Braga (ed.) Dynamic Laser Speckle and Applications • Giuliani, Bozzi-Pietra & Donati (2002) Self-mixing laser diode vibrometer Nicola Swindells

More Related