SlideShare a Scribd company logo
ARC- WHY DO THEY APPEAR IN
DIFFERENT SHADES..?
SLIDES PREPARED BY
OPTOM FASLU MUHAMMED
Why Choose an Anti-Reflection
Coating?
 As light passes through an uncoated glass
substrate, approximately 4% will be reflected at
each interface. This results in a total transmission
of only 92% of the incident light. Applying an AR
coating on each surface will increase the
throughput of the system and reduce hazards
caused by reflections traveling backwards
through the system (ghost images). Anti-
reflection coatings are especially important if the
system contains many transmitting optical
elements. Also, many low-light systems
incorporate AR coated optics to allow for
efficient use of light.
Fig. Illustration of Light
Interacting with Thin Film
How Does an Anti-Reflection
Coating Work?
 The transmission properties of a coating are dependent
upon the wavelength of light being used, the substrate's
index of refraction, the index of refraction of the coating,
the thickness of the coating, and the angle of the incident
light.
 The coating is designed so that the relative phase shift
between the beam reflected at the upper and lower
boundary of the thin film is 180°. Destructive interference
between the two reflected beams occurs, cancelling both
beams before they exit the surface. The optical thickness of
the coating must be an odd number of quarter wavelengths
(λ/4, where λ is the design wavelength or wavelength being
optimized for peak performance), in order to achieve the
desired path difference of one half wavelength between
the reflected beams, which leads to their cancellation.
Anti-Reflection Coating &
Its Color
 All AR lenses reflect a small amount of color, typically referred to as residual
color. Many AR lenses have a green residual color, while others have a blue or
yellow-green residual color.
 This phenomenon is associated with the reflectance curve of a broadband AR
coating across the visible spectrum of light. AR has a peak reflectance at some
point on the visible light spectrum (400–760 nm), and it is the color associated
with that peak that is reflected most. AR lenses with a green residual color tend
to have peak reflectance in the 520 - 550nm range, which is also the easiest color
to produce consistently. Some manufacturers move the curve peak closer to the
blue end of the spectrum, while others move the peak towards yellow. Most AR
producers choose their AR design and resulting peak color reflection based on
customer preference or visual performance goals. Eye sensitivity during daytime
or twilight has also been cited as criteria for residual color choice.
 The most common method to precisely measure the thickness of anti-reflection
coatings is using ellipsometry which looks at the way polarized light is reflected.
Fig. Color of silicon nitride films with a refractive index of ~2.05 as a
function of film thickness under fluorescent lighting for normal incident
light.
 Four multi crystalline wafers covered with films of silicon nitride.
The difference in color is solely due to the thickness of the film.
The green wafers are very thick films and so don't appear in the
color chart of the next figure.
 The color of the film is affected by the thickness as well as the
refractive index so the film color is merely a rough guide to
thickness. There are multiple tables for determining the films
thickness for films of silicon dioxide or silicon nitride such as
those shown below. It is common to fabricate film standards so
that variations in process conditions can be quickly detected by
comparing samples to the standard.
 The chart is merely a guide as the color of films on films in
commercial production will be affected by texturing and changes
in the refractive index
Color Chart for Films of Silicon Dioxide (SiO2)
under fluorescent lighting
FilmThickness (µm) Color
0.15 Light blue to metallic blue
0.17 Metallic to very light yellow green
0.30 Blue to violet blue
0.31 Blue
0.32 Blue to blue green
0.34 Light green
0.47 Violet
CONTENT PREPARED BY

More Related Content

What's hot

Progressive Spectacle Lens Fitting
Progressive Spectacle Lens FittingProgressive Spectacle Lens Fitting
Progressive Spectacle Lens Fitting
Vishakh Nair
 
Bifocal Spectacles..
Bifocal Spectacles..Bifocal Spectacles..
Bifocal Spectacles..
Vishakh Nair
 
Lens material and its propertes
Lens material and its propertesLens material and its propertes
Lens material and its propertes
Swati Panara
 

What's hot (20)

Lens material
Lens materialLens material
Lens material
 
Anti reflection coating
Anti reflection coatingAnti reflection coating
Anti reflection coating
 
Progressive Adition Lens
Progressive Adition LensProgressive Adition Lens
Progressive Adition Lens
 
Progressive addition lenses
Progressive addition lensesProgressive addition lenses
Progressive addition lenses
 
Progressive Spectacle Lens Fitting
Progressive Spectacle Lens FittingProgressive Spectacle Lens Fitting
Progressive Spectacle Lens Fitting
 
Decentration and prismatic effect in lens (1)
Decentration and prismatic effect in lens (1)Decentration and prismatic effect in lens (1)
Decentration and prismatic effect in lens (1)
 
Soft Contact Lenses: Material, Fitting, and Evaluation
Soft Contact Lenses: Material, Fitting, and EvaluationSoft Contact Lenses: Material, Fitting, and Evaluation
Soft Contact Lenses: Material, Fitting, and Evaluation
 
Slit Lamp Illumination Techniques
Slit Lamp Illumination TechniquesSlit Lamp Illumination Techniques
Slit Lamp Illumination Techniques
 
ophthalmic Lens material and design
ophthalmic Lens  material and designophthalmic Lens  material and design
ophthalmic Lens material and design
 
Polarized lenses
Polarized  lensesPolarized  lenses
Polarized lenses
 
Contact lens
Contact lensContact lens
Contact lens
 
Bifocal Spectacles..
Bifocal Spectacles..Bifocal Spectacles..
Bifocal Spectacles..
 
Soft Toric Contact lens
Soft Toric Contact lensSoft Toric Contact lens
Soft Toric Contact lens
 
3 Tests for Binocular Single Vision
3 Tests for Binocular Single Vision3 Tests for Binocular Single Vision
3 Tests for Binocular Single Vision
 
Examination protocol for binocular vision
Examination protocol for binocular visionExamination protocol for binocular vision
Examination protocol for binocular vision
 
Best form spectacle lenses
Best form spectacle lenses Best form spectacle lenses
Best form spectacle lenses
 
Multifocal contact lens
Multifocal contact lensMultifocal contact lens
Multifocal contact lens
 
Binocular balancing
Binocular balancing Binocular balancing
Binocular balancing
 
Frame adjustment and quality checking
Frame adjustment and quality checkingFrame adjustment and quality checking
Frame adjustment and quality checking
 
Lens material and its propertes
Lens material and its propertesLens material and its propertes
Lens material and its propertes
 

Similar to Arc ppt

Khepricoat product-brochure
Khepricoat product-brochureKhepricoat product-brochure
Khepricoat product-brochure
David Franz
 

Similar to Arc ppt (20)

Thin Film Analysis Using Shimadzu UV-2600
Thin Film Analysis Using Shimadzu UV-2600Thin Film Analysis Using Shimadzu UV-2600
Thin Film Analysis Using Shimadzu UV-2600
 
Lens enhancement considering for prescribing
Lens enhancement considering for prescribing Lens enhancement considering for prescribing
Lens enhancement considering for prescribing
 
Catalog VORTEX All About Optics | Optics Trade | 2014
Catalog VORTEX All About Optics | Optics Trade | 2014Catalog VORTEX All About Optics | Optics Trade | 2014
Catalog VORTEX All About Optics | Optics Trade | 2014
 
Medical Equipment lec 7 Radiography detectors
Medical Equipment lec 7 Radiography detectorsMedical Equipment lec 7 Radiography detectors
Medical Equipment lec 7 Radiography detectors
 
Lens enhancement
Lens enhancementLens enhancement
Lens enhancement
 
AR cooting.pptx
AR cooting.pptxAR cooting.pptx
AR cooting.pptx
 
Image quality
Image qualityImage quality
Image quality
 
Iluminacion
IluminacionIluminacion
Iluminacion
 
Small catadioptric microscope optics 2003
Small catadioptric microscope optics   2003Small catadioptric microscope optics   2003
Small catadioptric microscope optics 2003
 
Khepricoat product-brochure
Khepricoat product-brochureKhepricoat product-brochure
Khepricoat product-brochure
 
Radiographic Image contrast & image resolution
Radiographic Image contrast & image resolutionRadiographic Image contrast & image resolution
Radiographic Image contrast & image resolution
 
Flim screen physics
Flim screen physicsFlim screen physics
Flim screen physics
 
Tinted lenses
Tinted lensesTinted lenses
Tinted lenses
 
DSM KhepriCoat™ high transmission coatings
DSM KhepriCoat™ high transmission coatings DSM KhepriCoat™ high transmission coatings
DSM KhepriCoat™ high transmission coatings
 
LASERSMART™ Eye Protection: A Safety Primer Whitepaper
LASERSMART™ Eye Protection: A Safety Primer WhitepaperLASERSMART™ Eye Protection: A Safety Primer Whitepaper
LASERSMART™ Eye Protection: A Safety Primer Whitepaper
 
DSM KhepriCoat™ high transmission coating
DSM KhepriCoat™ high transmission coatingDSM KhepriCoat™ high transmission coating
DSM KhepriCoat™ high transmission coating
 
Optical fibres by Dr Praful D Shirbhate
Optical fibres by Dr Praful D ShirbhateOptical fibres by Dr Praful D Shirbhate
Optical fibres by Dr Praful D Shirbhate
 
Fiber optics 1-3
Fiber optics 1-3Fiber optics 1-3
Fiber optics 1-3
 
Variable Angle Reflectance & Transmittance of Thin Film Coatings
Variable Angle Reflectance & Transmittance of Thin Film CoatingsVariable Angle Reflectance & Transmittance of Thin Film Coatings
Variable Angle Reflectance & Transmittance of Thin Film Coatings
 
Brochure LUMINIT Acal BFi Novembre2017
Brochure LUMINIT Acal BFi Novembre2017Brochure LUMINIT Acal BFi Novembre2017
Brochure LUMINIT Acal BFi Novembre2017
 

More from OPTOM FASLU MUHAMMED

More from OPTOM FASLU MUHAMMED (20)

binocular balancing by optom faslu muhammed
binocular balancing by optom faslu muhammedbinocular balancing by optom faslu muhammed
binocular balancing by optom faslu muhammed
 
paediatric spectacle prescription by optom faslu muhammed
paediatric spectacle prescription by optom faslu muhammedpaediatric spectacle prescription by optom faslu muhammed
paediatric spectacle prescription by optom faslu muhammed
 
accommodative-convergence by jubairiya firoz
accommodative-convergence by jubairiya firozaccommodative-convergence by jubairiya firoz
accommodative-convergence by jubairiya firoz
 
assessment of vision in infants by optom faslu muhammed
assessment of vision in infants by optom faslu muhammedassessment of vision in infants by optom faslu muhammed
assessment of vision in infants by optom faslu muhammed
 
alchohol and eye by optom faslu muhammed
alchohol and eye by optom faslu muhammedalchohol and eye by optom faslu muhammed
alchohol and eye by optom faslu muhammed
 
blue light by optom faslu muhammed
 blue light by optom faslu muhammed blue light by optom faslu muhammed
blue light by optom faslu muhammed
 
smoking and eye problems by optom faslu muhammed
smoking and eye problems by optom faslu muhammedsmoking and eye problems by optom faslu muhammed
smoking and eye problems by optom faslu muhammed
 
multifocal contact lenses buy faslu muhammed
multifocal contact lenses buy faslu muhammedmultifocal contact lenses buy faslu muhammed
multifocal contact lenses buy faslu muhammed
 
eye bank by optom faslu muhammed
eye bank by optom faslu muhammedeye bank by optom faslu muhammed
eye bank by optom faslu muhammed
 
empty space myopia
empty space myopiaempty space myopia
empty space myopia
 
all about glaucoma
all about glaucomaall about glaucoma
all about glaucoma
 
Eye bank
Eye bankEye bank
Eye bank
 
Blue light
Blue lightBlue light
Blue light
 
Pregnancy and eye problems
Pregnancy and eye problemsPregnancy and eye problems
Pregnancy and eye problems
 
Jackson cross cylinder
Jackson cross cylinderJackson cross cylinder
Jackson cross cylinder
 
Log mar chart
Log mar chartLog mar chart
Log mar chart
 
Dispensing of ortho k lenses
Dispensing of ortho k lensesDispensing of ortho k lenses
Dispensing of ortho k lenses
 
Visual acuity
Visual acuityVisual acuity
Visual acuity
 
Vision standards for various occupation
Vision standards for various occupationVision standards for various occupation
Vision standards for various occupation
 
uvea
uveauvea
uvea
 

Recently uploaded

Cardiac Impulse: Rhythmical Excitation and Conduction in the Heart
Cardiac Impulse: Rhythmical Excitation and Conduction in the HeartCardiac Impulse: Rhythmical Excitation and Conduction in the Heart
Cardiac Impulse: Rhythmical Excitation and Conduction in the Heart
MedicoseAcademics
 

Recently uploaded (20)

180-hour Power Capsules For Men In Ghana
180-hour Power Capsules For Men In Ghana180-hour Power Capsules For Men In Ghana
180-hour Power Capsules For Men In Ghana
 
"Central Hypertension"‚ in China: Towards the nation-wide use of SphygmoCor t...
"Central Hypertension"‚ in China: Towards the nation-wide use of SphygmoCor t..."Central Hypertension"‚ in China: Towards the nation-wide use of SphygmoCor t...
"Central Hypertension"‚ in China: Towards the nation-wide use of SphygmoCor t...
 
Is preeclampsia and spontaneous preterm delivery associate with vascular and ...
Is preeclampsia and spontaneous preterm delivery associate with vascular and ...Is preeclampsia and spontaneous preterm delivery associate with vascular and ...
Is preeclampsia and spontaneous preterm delivery associate with vascular and ...
 
Couples presenting to the infertility clinic- Do they really have infertility...
Couples presenting to the infertility clinic- Do they really have infertility...Couples presenting to the infertility clinic- Do they really have infertility...
Couples presenting to the infertility clinic- Do they really have infertility...
 
Integrated Neuromuscular Inhibition Technique (INIT)
Integrated Neuromuscular Inhibition Technique (INIT)Integrated Neuromuscular Inhibition Technique (INIT)
Integrated Neuromuscular Inhibition Technique (INIT)
 
linearity concept of significance, standard deviation, chi square test, stude...
linearity concept of significance, standard deviation, chi square test, stude...linearity concept of significance, standard deviation, chi square test, stude...
linearity concept of significance, standard deviation, chi square test, stude...
 
Non-Invasive assessment of arterial stiffness in advanced heart failure patie...
Non-Invasive assessment of arterial stiffness in advanced heart failure patie...Non-Invasive assessment of arterial stiffness in advanced heart failure patie...
Non-Invasive assessment of arterial stiffness in advanced heart failure patie...
 
Relationship between vascular system disfunction, neurofluid flow and Alzheim...
Relationship between vascular system disfunction, neurofluid flow and Alzheim...Relationship between vascular system disfunction, neurofluid flow and Alzheim...
Relationship between vascular system disfunction, neurofluid flow and Alzheim...
 
NCLEX RN REVIEW EXAM CONTENT BLUE BOOK PDF
NCLEX RN REVIEW EXAM CONTENT BLUE BOOK PDFNCLEX RN REVIEW EXAM CONTENT BLUE BOOK PDF
NCLEX RN REVIEW EXAM CONTENT BLUE BOOK PDF
 
Young at heart: Cardiovascular health stations to empower healthy lifestyle b...
Young at heart: Cardiovascular health stations to empower healthy lifestyle b...Young at heart: Cardiovascular health stations to empower healthy lifestyle b...
Young at heart: Cardiovascular health stations to empower healthy lifestyle b...
 
Hemodialysis: Chapter 2, Extracorporeal Blood Circuit - Dr.Gawad
Hemodialysis: Chapter 2, Extracorporeal Blood Circuit - Dr.GawadHemodialysis: Chapter 2, Extracorporeal Blood Circuit - Dr.Gawad
Hemodialysis: Chapter 2, Extracorporeal Blood Circuit - Dr.Gawad
 
A thorough review of supernormal conduction.pptx
A thorough review of supernormal conduction.pptxA thorough review of supernormal conduction.pptx
A thorough review of supernormal conduction.pptx
 
The POPPY STUDY (Preconception to post-partum cardiovascular function in prim...
The POPPY STUDY (Preconception to post-partum cardiovascular function in prim...The POPPY STUDY (Preconception to post-partum cardiovascular function in prim...
The POPPY STUDY (Preconception to post-partum cardiovascular function in prim...
 
Aptopadesha Pramana / Pariksha: The Verbal Testimony
Aptopadesha Pramana / Pariksha: The Verbal TestimonyAptopadesha Pramana / Pariksha: The Verbal Testimony
Aptopadesha Pramana / Pariksha: The Verbal Testimony
 
Introducing VarSeq Dx as a Medical Device in the European Union
Introducing VarSeq Dx as a Medical Device in the European UnionIntroducing VarSeq Dx as a Medical Device in the European Union
Introducing VarSeq Dx as a Medical Device in the European Union
 
ANATOMY OF THE LOWER URINARY TRACT AND MALE [Autosaved] [Autosaved].pptx
ANATOMY OF THE LOWER URINARY TRACT AND MALE [Autosaved] [Autosaved].pptxANATOMY OF THE LOWER URINARY TRACT AND MALE [Autosaved] [Autosaved].pptx
ANATOMY OF THE LOWER URINARY TRACT AND MALE [Autosaved] [Autosaved].pptx
 
Cardiac Impulse: Rhythmical Excitation and Conduction in the Heart
Cardiac Impulse: Rhythmical Excitation and Conduction in the HeartCardiac Impulse: Rhythmical Excitation and Conduction in the Heart
Cardiac Impulse: Rhythmical Excitation and Conduction in the Heart
 
Arterial health throughout cancer treatment and exercise rehabilitation in wo...
Arterial health throughout cancer treatment and exercise rehabilitation in wo...Arterial health throughout cancer treatment and exercise rehabilitation in wo...
Arterial health throughout cancer treatment and exercise rehabilitation in wo...
 
Cervical screening – taking care of your health flipchart (Vietnamese)
Cervical screening – taking care of your health flipchart (Vietnamese)Cervical screening – taking care of your health flipchart (Vietnamese)
Cervical screening – taking care of your health flipchart (Vietnamese)
 
In-service education (Nursing Mangement)
In-service education (Nursing Mangement)In-service education (Nursing Mangement)
In-service education (Nursing Mangement)
 

Arc ppt

  • 1. ARC- WHY DO THEY APPEAR IN DIFFERENT SHADES..? SLIDES PREPARED BY OPTOM FASLU MUHAMMED
  • 2. Why Choose an Anti-Reflection Coating?  As light passes through an uncoated glass substrate, approximately 4% will be reflected at each interface. This results in a total transmission of only 92% of the incident light. Applying an AR coating on each surface will increase the throughput of the system and reduce hazards caused by reflections traveling backwards through the system (ghost images). Anti- reflection coatings are especially important if the system contains many transmitting optical elements. Also, many low-light systems incorporate AR coated optics to allow for efficient use of light.
  • 3. Fig. Illustration of Light Interacting with Thin Film
  • 4. How Does an Anti-Reflection Coating Work?  The transmission properties of a coating are dependent upon the wavelength of light being used, the substrate's index of refraction, the index of refraction of the coating, the thickness of the coating, and the angle of the incident light.  The coating is designed so that the relative phase shift between the beam reflected at the upper and lower boundary of the thin film is 180°. Destructive interference between the two reflected beams occurs, cancelling both beams before they exit the surface. The optical thickness of the coating must be an odd number of quarter wavelengths (λ/4, where λ is the design wavelength or wavelength being optimized for peak performance), in order to achieve the desired path difference of one half wavelength between the reflected beams, which leads to their cancellation.
  • 5. Anti-Reflection Coating & Its Color  All AR lenses reflect a small amount of color, typically referred to as residual color. Many AR lenses have a green residual color, while others have a blue or yellow-green residual color.  This phenomenon is associated with the reflectance curve of a broadband AR coating across the visible spectrum of light. AR has a peak reflectance at some point on the visible light spectrum (400–760 nm), and it is the color associated with that peak that is reflected most. AR lenses with a green residual color tend to have peak reflectance in the 520 - 550nm range, which is also the easiest color to produce consistently. Some manufacturers move the curve peak closer to the blue end of the spectrum, while others move the peak towards yellow. Most AR producers choose their AR design and resulting peak color reflection based on customer preference or visual performance goals. Eye sensitivity during daytime or twilight has also been cited as criteria for residual color choice.  The most common method to precisely measure the thickness of anti-reflection coatings is using ellipsometry which looks at the way polarized light is reflected.
  • 6. Fig. Color of silicon nitride films with a refractive index of ~2.05 as a function of film thickness under fluorescent lighting for normal incident light.
  • 7.  Four multi crystalline wafers covered with films of silicon nitride. The difference in color is solely due to the thickness of the film. The green wafers are very thick films and so don't appear in the color chart of the next figure.  The color of the film is affected by the thickness as well as the refractive index so the film color is merely a rough guide to thickness. There are multiple tables for determining the films thickness for films of silicon dioxide or silicon nitride such as those shown below. It is common to fabricate film standards so that variations in process conditions can be quickly detected by comparing samples to the standard.  The chart is merely a guide as the color of films on films in commercial production will be affected by texturing and changes in the refractive index
  • 8. Color Chart for Films of Silicon Dioxide (SiO2) under fluorescent lighting FilmThickness (µm) Color 0.15 Light blue to metallic blue 0.17 Metallic to very light yellow green 0.30 Blue to violet blue 0.31 Blue 0.32 Blue to blue green 0.34 Light green 0.47 Violet