Solar pumped Laser
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Transcript of Solar pumped Laser
Supervised By: Presented By:
Prof. D.S. Mehta Ajay Singh
Design and Development of Solar pumped Nd:YAG Laser
Typical Nd:YAG Laser
https://en.wikipedia.org/wiki/Laser_construction
Laser Rod(Active Media) Pumping source (flashtubes/
continuous gas discharge lamps/DPSS lasers
Laser Cavity & output coupler Power Supply
1
https://en.wikipedia.org/wiki/Laser_construction
Laser Rod(Active Media) Pumping source (flashtubes/
continuous gas discharge lamps/DPSS lasers
Laser Cavity & output coupler Power Supply
The Sunlight as pumping source 3.5 to 7.0 kWh/m2 per day Broad spectrum Not hazardous like mercury No power supply No dependence on electricity Available everywhere
Source:http://en.wikipedia.org/wiki/Sunlight#/media/File:Solar_spectrum_en.svg)
Typical Nd:YAG Laser1
Design of Solar pumped Nd:YAG Laser 2
Design of Solar pumped Nd:YAG Laser 2
Motivation:
Conversion of naturally available light
into laser light
Alternate pumping source for lasers
Ecofriendly system
System with “No power supply”
Low cost, field portable system
Green Photonics
Basic Requirements:
Collection of solar light
Transportation of the light
Laser cavity design
Laser pumping by the light
Oscillation/Amplification
Optimization !!
Design of Solar pumped Nd:YAG Laser 2
Motivation:
Fo
ca
l len
gth
Solar concentrator(Fresnel Lens)
Conversion of naturally available light
into laser light
Alternate pumping source for lasers
Ecofriendly system
System with “No power supply”
Low cost, field portable system
Green Photonics
Collection of solar light
Fresnel Lens concentrator
Focal length : 61cm
Diameter: 46 cm
Fresnel lens mount
Measured spot size~= 7mm
Groove density= 50 g/inch
Index of refraction= 1.49
Substrate=Acrylic
Transmission=92% (400-1000nm)
3
Collection of solar light
Fresnel Lens concentrator
Focal length : 61cm
Diameter: 46 cm
Fresnel lens mount
Measured spot size~= 7mm
Groove density= 50 g/inch
Index of refraction= 1.49
Substrate=Acrylic
Transmission=92% (400-1000nm)
Fresnel LensCollection of solar light3
Focal point
Collection of solar light
Fresnel Lens concentrator
Focal length : 61cm
Diameter: 46 cm
Fresnel lens mount
Measured spot size~= 7mm
Groove density= 50 g/inch
Index of refraction= 1.49
Substrate=Acrylic
Transmission=92% (400-1000nm)
Fresnel Lens
Focal point
Collection of solar light3
Why Fresnel lens ? Much thinner comparable to conventional lens Large aperture and short focal length Captures more oblique light from a light
source Reduces the amount of material required
compared to a conventional lens
Laser rod (The active media)
Neodymium-doped yttrium aluminium garnet (Nd:YAG)Nd:Y3Al5O12
Dopant Concentration: 1 %
Diameter: 5mm
Length: 50mm, 120mm
AR Coating: (R < 0.2% @ 1064 nm)
HR coating : (R >99% @ 1064nm)
Orientation: <111> +/- 5%
Surface Flatness: <λ/10@1064 nm
Damage Threshold: 500mW/cm2
Energy Level Diagram of Nd:YAG
4
Laser rod (The active media)
Neodymium-doped yttrium aluminium garnet (Nd:YAG)Nd:Y3Al5O12
Dopant Concentration: 1 %
Diameter: 5mm
Length: 50mm, 120mm
AR Coating: (R < 0.2% @ 1064 nm)
HR coating : (R >99% @ 1064nm)
Orientation: <111> +/- 5%
Surface Flatness: <λ/10@1064 nm
Damage Threshold: 500mW/cm2
Energy Level Diagram of Nd:YAG
https://www.rp-photonics.com/yag_lasers.html
Nd3+:YAG is a four-level gain medium:
substantial gain even for moderate
excitation [6]
The gain bandwidth is relatively small, but
this allows for a high gain efficiency and
thus low threshold pump power [6].
5
Light Guide
o Glass
o Conical end
o Total internal reflection
o Reflection
o Selective coating
o Other types of LG available
o Fused silica Light Guide
6
Laser rod
Light from concentrator
Light Guide
Laser rod
Light from concentrator
Cooling System
Water cooling
Attached to Light guide
Laser rod submerged into water
o Glass
o Conical end
o Total internal reflection
o Reflection
o Selective coating
o Other types of LG available
o Fused silica Light Guide
6
Source:http://en.wikipedia.org/wiki/Sunlight#/media/File
:Solar_spectrum_en.svg)
Light Guide
Cooling System
Water cooling
Attached to Light guide
Laser rod submerged into water
o Glass
o Conical end
o Total internal reflection
o Reflection
o Selective coating
o Other types of LG available
o Fused silica Light Guide
6
Laser rod
Light from concentrator
Water
Work Done So Far…. Fresnel lens mount
Procurement of Fresnel lens
Procurement of Laser rod
Focal length and Spot size measurement
Fabrication of light guide
Cooling system
Cavity design (on going )
7
Work Done So Far…. Fresnel lens mount
Procurement of Fresnel lens
Procurement of Laser rod
Focal length and Spot size measurement
Fabrication of light guide
Cooling system
Cavity design (on going )
Additional work
Light transport using fiber bundle
IR separation using prism
7
Future Work Plan 8
September
• Cavity Design
• Fix the laser rod in the cavity
October
• Inlet/outlet for cooling water
• Modify the light guide !!
November
• Pumping
• Measure and characterize theoutput
Next Semester
• Place output couplers
• Characterize the output
• Optimization
• Redesign
References:
[1]. J. Almeida, D. Liang, E. Guillot, and Y. Abdel-Hadi, “A 40 W cw Nd:YAG solar laserpumped through a heliostat: a parabolic mirror system,” Laser Phys. 23, 065801 (2013)[2]. Joana Almeidaa, Dawei Lianga and Emmanuel Guillotb, Improvement in solar-pumpedNd:YAG laser beam brightness, Optics and Laser technology ,Volume 44,Issue 7,October2012[3]. D. Liang and J. Almeida, Highly efficient solar-pumped Nd:YAG laser, Opt. Express 19(2011) 26399-26405[4]. L. Jing, H. Liu, Y. Wang, W. Xu, H. Zhang, and Z. Lu, “Design and optimization of Fresnellens for high concentration photovoltaic system,” Int. J. Photoenergy 14, 539891 (2014)[5]. http://nextbigfuture.com/2014/10/sola-powered-lasers-for-magnesium.html[6]. https://www.rp-photonics.com/yag_lasers.html[7]. http://fp.optics.arizona.edu/[8]. http://www.fizik.itu.edu.tr/akturks/files/L&P%2014%20laser%20types.pdf[9]. https://en.wikipedia.org/wiki/List_of_laser_types
Thank for your Attention!
Ray Diagram
Critical angle condition:Half angle= Sin-1(n1
2-n22)1/2= 63.44o for Glass
= 57.83o for Water
8
Future work
Plan
September
Cavity Design
Fix the laser rod in the cavity
October
Inlet/outlet for cooling water
Modify the light guide !!
November
Pumping
Measure and characterize the output
Next Semester
Output couplers
Measure the output and characterize
Optimization
Redesign !!