Total Internal Reflection - Revision history

Cmditradmin at 19:55, 29 December 2009

2009-12-29T19:55:21Z

← Older revision		Revision as of 12:55, 29 December 2009
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	<swf width="500" height="400">http://concave.stc.arizona.edu/thepoint/Interactive/ofiberapp2.swf</swf>		<swf width="500" height="400">http://concave.stc.arizona.edu/thepoint/Interactive/ofiberapp2.swf</swf>

			[[category:light]]
	<table id="toc" style="width: 100%">		<table id="toc" style="width: 100%">
	<tr>		<tr>

Cmditradmin: /* Total Internal Reflection */

2009-08-26T22:22:26Z

Total Internal Reflection

← Older revision		Revision as of 15:22, 26 August 2009
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	In this case there is no transmitted light in the second medium (the irradiance of the reflected and incident beams is equal). Light interacts at the interface and there is a phase shift between the incident and the reflected beams which is dependent on the two materials.		In this case there is no transmitted light in the second medium (the irradiance of the reflected and incident beams is equal). Light interacts at the interface and there is a phase shift between the incident and the reflected beams which is dependent on the two materials.

	~~tan psi~~


	This is a critical process in optical fibers and waveguides because it can carry light for long distances. For these values of index of refraction you get a critical angle of 78.6 which means the light must be very nearly parallel to the interface.		This is a critical process in optical fibers and waveguides because it can carry light for long distances. For these values of index of refraction you get a critical angle of 78.6 which means the light must be very nearly parallel to the interface.

Cmditradmin: /* Total Internal Reflection */

2009-08-26T22:21:11Z

Total Internal Reflection

← Older revision		Revision as of 15:21, 26 August 2009
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	~~If θ<sub>i~~<~~/sub~~> > ~~θ<sub>c~~</~~sub~~> ~~then~~ there is total reflection ~~and~~ there is no transmitted light in the second medium (the irradiance of the reflected and incident beams is equal). Light interacts at the interface and there is a phase shift between the incident and the reflected beams which is dependent on the two materials.		and when

			:<math>\theta_1 > \theta_{1c}\,\!</math> there is total reflection

			In this case there is no transmitted light in the second medium (the irradiance of the reflected and incident beams is equal). Light interacts at the interface and there is a phase shift between the incident and the reflected beams which is dependent on the two materials.

	tan psi		tan psi

Cmditradmin: /* Total Internal Reflection */

2009-08-26T22:18:21Z

Total Internal Reflection

← Older revision		Revision as of 15:18, 26 August 2009
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	for a critical angle Θ<sub>1</sub>, Θ<sub>2</sub> = 90°and the beam emerges along the surface		for a critical angle Θ<sub>1</sub>, Θ<sub>2</sub> = 90°and the beam emerges along the surface

	When ~~θ~~<~~sub>2</sub~~> = 90° ~~→~~ sin ~~θ~~<~~sub~~>2<~~/sub~~> = 1		When

			:<math>\theta_2 = 90° \rightarrow sin \theta_2 = 1\,\!</math>

			:<math>\theta_{1c} = sin^{-1} \left (\frac {n_2} {n_1} \right )\,\!</math>

Cmditradmin: /* Total Internal Reflection */

2009-08-26T22:15:35Z

Total Internal Reflection

← Older revision		Revision as of 15:15, 26 August 2009
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	[[Image:Snellslaw.png\|thumb\|300px\| When θ<sub>1</sub> > θ<sub>1c</sub> light can not enter medium n<sub>2</sub>]]		[[Image:Snellslaw.png\|thumb\|300px\| When θ<sub>1</sub> > θ<sub>1c</sub> light can not enter medium n<sub>2</sub>]]

	A critical concept in the case of optical fibers is the ~~case~~ total internal reflection. The bending of light as it goes into ~~medium~~ is related to the index of reflection of the materials (n<sub>1</sub> and n<sub>2</sub>). By Snell's law when n<sub>1</sub> > n<sub>2</sub> then θ <sub>1</sub> is less than θ<sub>2</sub>. As you decrease the angle θ<sub>1</sub> and bring the light closer to parallel with the interface you reach a critical angle θ<sub>1c</sub> where there is total internal reflection.		A critical concept in the case of optical fibers is the concept of total internal reflection. The bending of light as it goes from one medium into another is related to the index of reflection of the materials (n<sub>1</sub> and n<sub>2</sub>). By Snell's law when n<sub>1</sub> > n<sub>2</sub> then θ <sub>1</sub> is less than θ<sub>2</sub>. As you decrease the angle θ<sub>1</sub> and bring the light closer to parallel with the interface you reach a critical angle θ<sub>1c</sub> where there is total internal reflection.

	Snells laws are also known as Fresnel's Equations:		Snells laws are also known as Fresnel's Equations:
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	where		where
	:<math>\theta_i\,\!</math> is the angle of incidence		:<math>\theta_i\,\!</math> is the angle of incidence

	:<math>\theta_r\,\!</math> is the angle of reflection		:<math>\theta_r\,\!</math> is the angle of reflection

Cmditradmin: /* Total Internal Reflection */

2009-08-24T16:41:56Z

Total Internal Reflection

← Older revision		Revision as of 09:41, 24 August 2009
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	for n<sub>1</sub> = 1.53 and n<sub>2</sub> = 1.50 : θ<sub>1c</sub> = 78.6°		for n<sub>1</sub> = 1.53 and n<sub>2</sub> = 1.50 : θ<sub>1c</sub> = 78.6°

	[[Image:Wavelength_inside.jpg\|thumb\|300px\|As light passes from a vacuum into a medium with an index of refraction of 2, the wavelength get cut in half, and therefore it will take twice as long for to get through the medium. Again the frequency does not change.]]

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Cmditradmin at 20:29, 18 August 2009

2009-08-18T20:29:54Z

← Older revision		Revision as of 13:29, 18 August 2009
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			=== Simulations ===


			This flash simulation shows how total internal reflection and minimum radius of turns depends on the diameter of the optical fiber. The diameter changes how much of the light is below the critical angle where it is fully reflected.

			<swf width="500" height="400">http://concave.stc.arizona.edu/thepoint/Interactive/ofiber.swf</swf>


			This simulation allows you to select combinations of materials with different indexes of refraction. Try to get the best combination to achieve total internal reflection.
			<swf width="500" height="400">http://concave.stc.arizona.edu/thepoint/Interactive/ofiberapp2.swf</swf>

Cmditradmin: /* Simulations */

2009-08-18T20:28:17Z

Simulations

← Older revision		Revision as of 13:28, 18 August 2009
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	<br clear='all'>		<br clear='all'>

	~~=== Simulations ===~~


	This flash simulation shows how total internal reflection and minimum radius of turns depends on the diameter of the optical fiber. The diameter changes how much of the light is below the critical angle where it is fully reflected.

	~~<swf width="500" height="400">http://concave.stc.arizona.edu/thepoint/Interactive/ofiber.swf</swf>~~


	~~This simulation allows you to select combinations of materials with different indexes of refraction. Try to get the best combination to achieve total internal reflection.~~
	~~<swf width="500" height="400">http://concave.stc.arizona.edu/thepoint/Interactive/ofiberapp2.swf</swf>~~

Cmditradmin at 22:41, 6 August 2009

2009-08-06T22:41:51Z

← Older revision		Revision as of 15:41, 6 August 2009
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	This simulation allows you to select combinations of materials with different indexes of refraction. Try to get the best combination to achieve total internal reflection.		This simulation allows you to select combinations of materials with different indexes of refraction. Try to get the best combination to achieve total internal reflection.
	<swf width="500" height="400">http://concave.stc.arizona.edu/thepoint/Interactive/ofiberapp2.swf</swf>		<swf width="500" height="400">http://concave.stc.arizona.edu/thepoint/Interactive/ofiberapp2.swf</swf>


	<table id="toc" style="width: 100%">		<table id="toc" style="width: 100%">
	<tr>		<tr>
	<td style="text-align: left; width: 33%">[[~~Reflection and Refraction~~\|Previous Topic]]</td>		<td style="text-align: left; width: 33%">[[Optical Fibers\|Previous Topic]]</td>
	<td style="text-align: center; width: 33%">[[Main_Page#~~Basics of Light~~\|Return to ~~Basics of Light~~ Menu]]</td>		<td style="text-align: center; width: 33%">[[Main_Page#Optical Fibers, Waveguides, and Lasers\|Return to Optical Fibers, Waveguides, and Lasers Menu]]</td>
	<td style="text-align: right; width: 33%">[[~~Dispersion and Scattering of Light~~\|Next Topic]]</td>		<td style="text-align: right; width: 33%">[[Planar Dielectric Waveguides\|Next Topic]]</td>
	</tr>		</tr>
	</table>		</table>

Cmditradmin at 22:40, 6 August 2009

2009-08-06T22:40:21Z

← Older revision		Revision as of 15:40, 6 August 2009
Line 1:		Line 1:
	<table id="toc" style="width: 100%">		<table id="toc" style="width: 100%">
	<tr>		<tr>
	<td style="text-align: left; width: 33%">[[~~Reflection and Refraction~~\|Previous Topic]]</td>		<td style="text-align: left; width: 33%">[[Optical Fibers\|Previous Topic]]</td>
	<td style="text-align: center; width: 33%">[[Main_Page#~~Basics of Light~~\|Return to ~~Basics of Light~~ Menu]]</td>		<td style="text-align: center; width: 33%">[[Main_Page#Optical Fibers, Waveguides, and Lasers\|Return to Optical Fibers, Waveguides, and Lasers Menu]]</td>
	<td style="text-align: right; width: 33%">[[~~Dispersion and Scattering of Light~~\|Next Topic]]</td>		<td style="text-align: right; width: 33%">[[Planar Dielectric Waveguides\|Next Topic]]</td>
	</tr>		</tr>
	</table>		</table>