User:Pranav Rathi/Notebook/OT/2010/04/13/Mode profiling at high power - Revision history

Pranav Rathi: /* Result */

Pranav Rathi — Mon, 19 Nov 2012 23:15:18 GMT

Result

←Older revision		Revision as of 23:15, 19 November 2012
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	<html><iframe height="400px" width=800px" src="https://www.evernote.com/pub/pranavrathi1/beamprofilevstemp#b=5bc82a7e-657a-420f-adaf-fbb64cfa1ef4&n=d9228478-3b01-4977-8048-08d81ceff983		<html><iframe height="400px" width=800px" src="https://www.evernote.com/pub/pranavrathi1/beamprofilevstemp#b=5bc82a7e-657a-420f-adaf-fbb64cfa1ef4&n=d9228478-3b01-4977-8048-08d81ceff983
	"></iframe></html>		"></iframe></html>
		+	The result is linked here:[https://www.evernote.com/pub/pranavrathi1/beamprofilevstemp#b=5bc82a7e-657a-420f-adaf-fbb64cfa1ef4&n=d9228478-3b01-4977-8048-08d81ceff983]

	Well according to the pictures the beam profile does not look good at any temperature. At and above 70<sup>o</sup> the profile has distinctive higher order modes. Profile at 85<sup>o</sup> for 2W and 4W look completely different.		Well according to the pictures the beam profile does not look good at any temperature. At and above 70<sup>o</sup> the profile has distinctive higher order modes. Profile at 85<sup>o</sup> for 2W and 4W look completely different.

Pranav Rathi: /* Introduction */

Pranav Rathi — Mon, 19 Nov 2012 17:51:15 GMT

Introduction

←Older revision		Revision as of 17:51, 19 November 2012
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	====Introduction====		====Introduction====
-	Correct beam profile is very important for optical trap; in our case its (0, 0) Gaussian mode. It looks like that at high powers our laser moves to higher modes, which introduces some extra difficulties in focusing and getting diffraction limited spot~~. It is~~ also not good for the stiffness ~~calibration~~. The motivation behind doing this experiment is to answer some questions. The laser temperature was kept constant around 85<sup>o</sup> Fahrenheit.	+	Correct beam profile is very important for optical trap; in our case its (0, 0) Gaussian mode. It looks like that at high powers our laser moves to higher modes, which introduces some extra difficulties in focusing and getting diffraction limited spot and also not good for the stiffness determination. The motivation behind doing this experiment is to answer some questions. The laser temperature was kept constant around 85<sup>o</sup> Fahrenheit.

	====Motivation====		====Motivation====

Pranav Rathi: /* Conclusion */

Pranav Rathi — Thu, 15 Nov 2012 22:20:08 GMT

Conclusion

←Older revision		Revision as of 22:20, 15 November 2012
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	Answers to the question:		Answers to the question:

-	1.At what temperature beam starts getting out of single mode?	+	1. Q:At what temperature beam starts getting out of single mode?
-	At no temperature beam looks good.	+
-	2.What is the safest highest output power at the lowest laser temperature?	+	A: At no temperature beam looks good.
-	Since at no temperature the beam looks good at 4W output power so i doubt it that we can use power higher then 2W at any temperature.	+
		+	2. Q:What is the safest highest output power at the lowest laser temperature?
		+
		+	A:Since at no temperature the beam looks good at 4W output power so i doubt it that we can use power higher then 2W at any temperature.

	Looks like temperature makes only a tiny difference, so i am not comfortable using the laser above 2W even at the lowest achievable temperature.		Looks like temperature makes only a tiny difference, so i am not comfortable using the laser above 2W even at the lowest achievable temperature.

	[[Category:1064crystalaser]]		[[Category:1064crystalaser]]

Pranav Rathi: /* Conclusion */

Pranav Rathi — Thu, 15 Nov 2012 22:18:48 GMT

Conclusion

←Older revision		Revision as of 22:18, 15 November 2012
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	====Conclusion====		====Conclusion====
		+
	Answers to the questions:		Answers to the questions:
		+
	1. Q: At what output power the beam profile starts changing?		1. Q: At what output power the beam profile starts changing?
		+
	A: At 2W the profile starts changing and the change is significant above 2.3W.		A: At 2W the profile starts changing and the change is significant above 2.3W.
		+
	2. Q: Is the change slow with power?		2. Q: Is the change slow with power?
		+
	A: The change is slow but the higher order mode profile can only be seen after 3.2W.		A: The change is slow but the higher order mode profile can only be seen after 3.2W.
		+
	3. Q: How much does it change at 4.1W in comparison to the point at which it starts changing?		3. Q: How much does it change at 4.1W in comparison to the point at which it starts changing?
		+
	A: At 4.1W it looks completely different. (0, 1) mode profile can clearly seen with (0, 0) and possibly other higher order mode profiles in the back ground.		A: At 4.1W it looks completely different. (0, 1) mode profile can clearly seen with (0, 0) and possibly other higher order mode profiles in the back ground.
		+
	4. Q: What is the appropriate power range for tweezing?		4. Q: What is the appropriate power range for tweezing?
		+
	A: By looking the profiles, their looks like that up to 1.7/2.0W. But the		A: By looking the profiles, their looks like that up to 1.7/2.0W. But the
	exact boundary line can only be decided after doing the SUM Signal Experiment; the next task.		exact boundary line can only be decided after doing the SUM Signal Experiment; the next task.

Pranav Rathi: /* Conclusion */

Pranav Rathi — Thu, 15 Nov 2012 22:17:20 GMT

Conclusion

←Older revision		Revision as of 22:17, 15 November 2012
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	====Conclusion====		====Conclusion====
	Answers to the questions:		Answers to the questions:
-	# Q: At what output power the beam profile starts changing?	+	1. Q: At what output power the beam profile starts changing?
	A: At 2W the profile starts changing and the change is significant above 2.3W.		A: At 2W the profile starts changing and the change is significant above 2.3W.
-	# Q: Is the change slow with power?	+	2. Q: Is the change slow with power?
	A: The change is slow but the higher order mode profile can only be seen after 3.2W.		A: The change is slow but the higher order mode profile can only be seen after 3.2W.
-	# Q: How much does it change at 4.1W in comparison to the point at which it starts changing?	+	3. Q: How much does it change at 4.1W in comparison to the point at which it starts changing?
	A: At 4.1W it looks completely different. (0, 1) mode profile can clearly seen with (0, 0) and possibly other higher order mode profiles in the back ground.		A: At 4.1W it looks completely different. (0, 1) mode profile can clearly seen with (0, 0) and possibly other higher order mode profiles in the back ground.
-	# Q: What is the appropriate power range for tweezing?	+	4. Q: What is the appropriate power range for tweezing?
	A: By looking the profiles, their looks like that up to 1.7/2.0W. But the		A: By looking the profiles, their looks like that up to 1.7/2.0W. But the
	exact boundary line can only be decided after doing the SUM Signal Experiment; the next task.		exact boundary line can only be decided after doing the SUM Signal Experiment; the next task.

Pranav Rathi: /* Conclusion */

Pranav Rathi — Thu, 15 Nov 2012 22:16:35 GMT

Conclusion

←Older revision		Revision as of 22:16, 15 November 2012
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	Answers to the question:		Answers to the question:

-	#At what temperature beam starts getting out of single mode?	+	1.At what temperature beam starts getting out of single mode?
	At no temperature beam looks good.		At no temperature beam looks good.
-	#What is the safest highest output power at the lowest laser temperature?	+	2.What is the safest highest output power at the lowest laser temperature?
	Since at no temperature the beam looks good at 4W output power so i doubt it that we can use power higher then 2W at any temperature.		Since at no temperature the beam looks good at 4W output power so i doubt it that we can use power higher then 2W at any temperature.

Pranav Rathi: /* Conclusion */

Pranav Rathi — Thu, 15 Nov 2012 22:14:27 GMT

Conclusion

←Older revision		Revision as of 22:14, 15 November 2012
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	====Conclusion====		====Conclusion====
		+	Answers to the question:

		+	#At what temperature beam starts getting out of single mode?
		+	At no temperature beam looks good.
		+	#What is the safest highest output power at the lowest laser temperature?
		+	Since at no temperature the beam looks good at 4W output power so i doubt it that we can use power higher then 2W at any temperature.
		+
		+	Looks like temperature makes only a tiny difference, so i am not comfortable using the laser above 2W even at the lowest achievable temperature.

	[[Category:1064crystalaser]]		[[Category:1064crystalaser]]

Pranav Rathi: /* Result */

Pranav Rathi — Thu, 15 Nov 2012 22:08:12 GMT

Result

←Older revision		Revision as of 22:08, 15 November 2012
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	"></iframe></html>		"></iframe></html>

		+	Well according to the pictures the beam profile does not look good at any temperature. At and above 70<sup>o</sup> the profile has distinctive higher order modes. Profile at 85<sup>o</sup> for 2W and 4W look completely different.
		+
		+	====Conclusion====


	[[Category:1064crystalaser]]		[[Category:1064crystalaser]]

Pranav Rathi: /* Motivation */

Pranav Rathi — Thu, 15 Nov 2012 21:58:24 GMT

Motivation

←Older revision		Revision as of 21:58, 15 November 2012
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	# At what temperature beam starts getting out of single mode?		# At what temperature beam starts getting out of single mode?
	# What is the safest highest output power at the lowest laser temperature?		# What is the safest highest output power at the lowest laser temperature?
		+
		+	====Result====
		+	<html><iframe height="400px" width=800px" src="https://www.evernote.com/pub/pranavrathi1/beamprofilevstemp#b=5bc82a7e-657a-420f-adaf-fbb64cfa1ef4&n=d9228478-3b01-4977-8048-08d81ceff983
		+	"></iframe></html>
		+
		+

	[[Category:1064crystalaser]]		[[Category:1064crystalaser]]

Pranav Rathi: /* Introduction */

Pranav Rathi — Thu, 15 Nov 2012 21:56:18 GMT

Introduction

←Older revision		Revision as of 21:56, 15 November 2012
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	The purpose of this experiment is to establish a relationship between laser temperature and beam profile. In my tests sofar, i have seen a correlation between temperate and laser going to higher modes at some power. I want to explore the possibility of using higher powers at lower temperature without laser being tripped into higher modes.		The purpose of this experiment is to establish a relationship between laser temperature and beam profile. In my tests sofar, i have seen a correlation between temperate and laser going to higher modes at some power. I want to explore the possibility of using higher powers at lower temperature without laser being tripped into higher modes.

-	The beam profiling is done at several laser temperature with constant laser power output of 4W. The 2nd order diffraction beam is chosen for profiling at around 110mW. The temperature of the laser was modulated using TEC peltier.	+	The beam profiling is done at several laser temperature with constant laser power output of 4W. The 2nd order diffraction beam is chosen for profiling at around 110mW. The temperature of the laser was modulated using TEC peltier. The optical setup and procedure is same.

	====Motivation====		====Motivation====