Attenuated Total Reflectance - Revision history

Cmditradmin at 16:00, 5 October 2011

2011-10-05T16:00:06Z

← Older revision		Revision as of 09:00, 5 October 2011
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	Click Auto graph to record the diode current and the sample lockin voltage across a range of angles from -12 to 0 ( -2800 to 0 microsteps). Repeat this measurement at various field strengths to see the effect on the diode current.		Click Auto graph to record the diode current and the sample lockin voltage across a range of angles from -12 to 0 ( -2800 to 0 microsteps). Repeat this measurement at various field strengths to see the effect on the diode current.

	~~=== Technique ===~~
	~~{{#ev:youtube\|0BT3jHKodZY}}~~

	[[Image:Wet spot.JPG\|thumb\|300px\|In the prism coupling technique the sample is pressed between a prism and light pipe connected to a detector. The "wet spot" is the point where the light pipe is in perfect contact with the sample so they behave as a single unit. ]]

	=== Significance ===		=== Significance ===
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	:<math>n_{TM}\,\!</math> is the film refractive index		:<math>n_{TM}\,\!</math> is the film refractive index

			=== Technique ===
			{{#ev:youtube\|0BT3jHKodZY}}

			[[Image:Wet spot.JPG\|thumb\|300px\|In the prism coupling technique the sample is pressed between a prism and light pipe connected to a detector. The "wet spot" is the point where the light pipe is in perfect contact with the sample so they behave as a single unit. ]]
	=== References ===		=== References ===
	<references/>		<references/>

Cmditradmin: /* Technique */

2011-10-05T15:59:25Z

Technique

← Older revision		Revision as of 08:59, 5 October 2011
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	=== Technique ===		=== Technique ===
	~~Part 1 Sample Setup and calibration~~		{{#ev:youtube\|0BT3jHKodZY}}
	{{#ev:youtube\|~~2-Wc2QpLCa0}}~~

	~~Part 2 Measurement and analysis~~
	~~{{#ev:youtube\|P7BxIcl-9UM~~}}

	[[Image:Wet spot.JPG\|thumb\|300px\|In the prism coupling technique the sample is pressed between a prism and light pipe connected to a detector. The "wet spot" is the point where the light pipe is in perfect contact with the sample so they behave as a single unit. ]]		[[Image:Wet spot.JPG\|thumb\|300px\|In the prism coupling technique the sample is pressed between a prism and light pipe connected to a detector. The "wet spot" is the point where the light pipe is in perfect contact with the sample so they behave as a single unit. ]]

Cmditradmin: /* Technique */

2010-11-22T18:52:06Z

Technique

← Older revision		Revision as of 11:52, 22 November 2010
Line 20:		Line 20:

	=== Technique ===		=== Technique ===



	Part 1 Sample Setup and calibration		Part 1 Sample Setup and calibration
	{{#ev:youtube\|2-Wc2QpLCa0}}		{{#ev:youtube\|2-Wc2QpLCa0}}
Line 28:		Line 25:
	Part 2 Measurement and analysis		Part 2 Measurement and analysis
	{{#ev:youtube\|P7BxIcl-9UM}}		{{#ev:youtube\|P7BxIcl-9UM}}

			[[Image:Wet spot.JPG\|thumb\|300px\|In the prism coupling technique the sample is pressed between a prism and light pipe connected to a detector. The "wet spot" is the point where the light pipe is in perfect contact with the sample so they behave as a single unit. ]]

	=== Significance ===		=== Significance ===

128.95.39.187: /* Overview */

2010-03-11T17:43:23Z

Overview

@@ Line 4: / Line 4: @@
 === Overview ===
 Attenuated Total Reflection or ATR is a technique used together with Teng Mann to measure the R33 of electro-optic materials. A beam of IR light is directed through a prism at an angle exceeding the critical angle for internal reflection. This produces an evanescent wave at the prism surface. If a EO polymer is pressed in intimate contact with the prism they can be coupled so that he evanescent wave stimulates emission from the sample. This emission is measured with a photodiode. An electric field applied to an EO polymer changes its index of refraction which alters the critical angle.
 === Technique ===

128.95.39.187: /* Technique */

2010-03-11T17:43:08Z

Technique

← Older revision		Revision as of 10:43, 11 March 2010
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	=== Technique ===		=== Technique ===
	~~<div id="Flash">Attenuated Total Reflection simulation</div>~~

	~~<swf width="720" height="480">http://depts.washington.edu/cmditr/media/atr.swf</swf>~~

	~~The above simulation allows you visualize what is happening during ATR measurement.~~

	The EO material sample is pressed against the prism by the pneumatic plunger. The angle of the prism with respect to the laser is controlled with the slide bar. 0 degrees means the edge of the prism is normal to the laser beam and the sample is 45 degrees from the beam.

	~~The photodiode produces a current when there is reflection from the sample. At certain critical angles the sample traps light due to total internal reflection and its reflectance is attenuated.~~

	~~The field strength to the sample is controlled with the other slide 0-10 volts. This controls the EO effect in the sample.~~

	Click Auto graph to record the diode current and the sample lockin voltage across a range of angles from -12 to 0 ( -2800 to 0 microsteps). Repeat this measurement at various field strengths to see the effect on the diode current.

128.95.39.187: /* Technique */

2010-03-11T17:42:44Z

Technique

← Older revision		Revision as of 10:42, 11 March 2010
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	Part 1		Part 1 Sample Setup and calibration
	{{#ev:youtube\|2-Wc2QpLCa0}}		{{#ev:youtube\|2-Wc2QpLCa0}}

	Part 2		Part 2 Measurement and analysis
	{{#ev:youtube\|P7BxIcl-9UM}}		{{#ev:youtube\|P7BxIcl-9UM}}

Smhunter: /* Technique */

2010-03-04T19:03:36Z

Technique

← Older revision		Revision as of 12:03, 4 March 2010
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	Part 2		Part 2
	{{#ev:youtube\|P7BxIcl-9UM}		{{#ev:youtube\|P7BxIcl-9UM}}

	=== Significance ===		=== Significance ===

Smhunter: /* Technique */

2010-03-04T19:03:07Z

Technique

← Older revision		Revision as of 12:03, 4 March 2010
Line 19:		Line 19:

	Click Auto graph to record the diode current and the sample lockin voltage across a range of angles from -12 to 0 ( -2800 to 0 microsteps). Repeat this measurement at various field strengths to see the effect on the diode current.		Click Auto graph to record the diode current and the sample lockin voltage across a range of angles from -12 to 0 ( -2800 to 0 microsteps). Repeat this measurement at various field strengths to see the effect on the diode current.


			Part 1
			{{#ev:youtube\|2-Wc2QpLCa0}}

			Part 2
			{{#ev:youtube\|P7BxIcl-9UM}

	=== Significance ===		=== Significance ===

128.95.39.187 at 20:31, 12 February 2010

2010-02-12T20:31:12Z

← Older revision		Revision as of 13:31, 12 February 2010
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			<table id="toc" style="width: 100%">
			<tr>
			<td style="text-align: center; width: 33%">[[Main_Page#Research Equipment, Devices and Techniques\|Return to Research Tool Menu]]</td>
	=== Overview ===		=== Overview ===
	Attenuated Total Reflection or ATR is a technique used together with Teng Mann to measure the R33 of electro-optic materials. A beam of IR light is directed through a prism at an angle exceeding the critical angle for internal reflection. This produces an evanescent wave at the prism surface. If a EO polymer is pressed in intimate contact with the prism they can be coupled so that he evanescent wave stimulates emission from the sample. This emission is measured with a photodiode. An electric field applied to an EO polymer changes its index of refraction which alters the critical angle.		Attenuated Total Reflection or ATR is a technique used together with Teng Mann to measure the R33 of electro-optic materials. A beam of IR light is directed through a prism at an angle exceeding the critical angle for internal reflection. This produces an evanescent wave at the prism surface. If a EO polymer is pressed in intimate contact with the prism they can be coupled so that he evanescent wave stimulates emission from the sample. This emission is measured with a photodiode. An electric field applied to an EO polymer changes its index of refraction which alters the critical angle.

67.183.23.184: /* Technique */

2010-01-18T17:35:38Z

Technique

← Older revision		Revision as of 10:35, 18 January 2010
Line 11:		Line 11:
	The EO material sample is pressed against the prism by the pneumatic plunger. The angle of the prism with respect to the laser is controlled with the slide bar. 0 degrees means the edge of the prism is normal to the laser beam and the sample is 45 degrees from the beam.		The EO material sample is pressed against the prism by the pneumatic plunger. The angle of the prism with respect to the laser is controlled with the slide bar. 0 degrees means the edge of the prism is normal to the laser beam and the sample is 45 degrees from the beam.

	The photodiode produces a current when there is ~~relfection~~ from the sample. At certain critical angles the sample traps light due to total internal reflection and its reflectance is attenuated.		The photodiode produces a current when there is reflection from the sample. At certain critical angles the sample traps light due to total internal reflection and its reflectance is attenuated.

	The field strength to the sample is controlled with the other slide 0-10 volts. This controls the EO effect in the sample.		The field strength to the sample is controlled with the other slide 0-10 volts. This controls the EO effect in the sample.