Optical Chaos with External Feedback Mirror - Revision history

Aplstudent: /* Results */

2015-12-14T23:20:52Z

‎Results

Aplstudent: /* Sources */

2015-12-14T23:18:59Z

‎Sources

Aplstudent: /* Sources */

2015-12-14T23:18:37Z

‎Sources

Aplstudent: /* Sources */

2015-12-14T23:18:16Z

‎Sources

Aplstudent: /* Sources */

2015-12-14T23:17:57Z

‎Sources

Aplstudent: /* Sources */

2015-12-14T23:16:40Z

‎Sources

Aplstudent: /* Results */

2015-12-14T23:13:43Z

‎Results

Aplstudent: /* Results */

2015-12-14T23:06:58Z

‎Results

Aplstudent: /* Results */

2015-12-14T23:02:38Z

‎Results

Aplstudent: /* Results */

2015-12-14T22:50:37Z

‎Results

@@ Line 81: / Line 81: @@
 But what was evident to me towards the end of experiment was that there is no clear data for the mid-chaotic regime.  This I think was caused by the creation of a cavity between the mirror and the worn APC face of the SL pigtail (about a meter shorter than the desired SL-mirror cavity).  I base this on the fact that when I plugged the APC pigtail face through the 5m VOA and to the PD, I got an unwarranted external cavity with a frequency of 14MHz.  This should not happen.
-So, in summary, if you look at the highest regime of feedback that I tested, you should see evidence of a cavity disappearing as the laser power increases.  However, if good chaotic feedback was attained in the lower dynamics is questionable, since the strong peaks seem to indicate a cavity that "locked" out these tiny signals.
+So, in summary, if you look at the highest regime of feedback that I tested, you should see evidence of a cavity disappearing as the laser power increases.  However, it is questionable if good chaotic feedback was attained in the lower dynamics, since the strong peaks seem to indicate a cavity that "locked" out these tiny signals.
 Finally, here is a picture of the first chaos that I achieved, at about 45uW.

@@ Line 93: / Line 93: @@
 I highly recommend the use of the textbook "OPTICAL COMMUNICATION WITH CHAOTIC LASERS" by Atsushi Uchida (Wiley-VCH 2012).
 All the diagrams shown here were taken from the book.  It can be accessed online with UO student access.  (I found it by going to the UO Library site, searching for the title, which took me to ebrary.com, where it is available for download. Read it online, or offline with adobe digital editions reader.
 [[File:Ohtsube.jpg]]
 Also of assistance was "SEMICONDUCTOR LASERS: Stability, Instability and Chaos" by Junji Ohtsubo (Springer 2008).

@@ Line 89: / Line 89: @@
 = Sources =
-[[File:Uchida.JPG|100px]]
+[[File:Uchida.JPG|200px]]
 I highly recommend the use of the textbook "OPTICAL COMMUNICATION WITH CHAOTIC LASERS" by Atsushi Uchida (Wiley-VCH 2012).
 All the diagrams shown here were taken from the book.  It can be accessed online with UO student access.  (I found it by going to the UO Library site, searching for the title, which took me to ebrary.com, where it is available for download. Read it online, or offline with adobe digital editions reader.

@@ Line 89: / Line 89: @@
 = Sources =
-[[File:Uchida.JPG|450px]]
+[[File:Uchida.JPG|100px]]
 I highly recommend the use of the textbook "OPTICAL COMMUNICATION WITH CHAOTIC LASERS" by Atsushi Uchida (Wiley-VCH 2012).
 All the diagrams shown here were taken from the book.  It can be accessed online with UO student access.  (I found it by going to the UO Library site, searching for the title, which took me to ebrary.com, where it is available for download. Read it online, or offline with adobe digital editions reader.

@@ Line 89: / Line 89: @@
 = Sources =
-[[File:Uchida.JPG]]
+[[File:Uchida.JPG|450px]]
 I highly recommend the use of the textbook "OPTICAL COMMUNICATION WITH CHAOTIC LASERS" by Atsushi Uchida (Wiley-VCH 2012).
 All the diagrams shown here were taken from the book.  It can be accessed online with UO student access.  (I found it by going to the UO Library site, searching for the title, which took me to ebrary.com, where it is available for download. Read it online, or offline with adobe digital editions reader.
+[[File:Ohtsube.jpg]]
 Also of assistance was "SEMICONDUCTOR LASERS: Stability, Instability and Chaos" by Junji Ohtsubo (Springer 2008).

← Older revision		Revision as of 23:13, 14 December 2015
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	[[File:Chaos.jpeg\|450px]]		[[File:Chaos.jpeg\|450px]]
		+
		+	= Sources =
		+
		+
		+	I highly recommend the use of the textbook "OPTICAL COMMUNICATION WITH CHAOTIC LASERS" by Atsushi Uchida (Wiley-VCH 2012).
		+	All the diagrams shown here were taken from the book. It can be accessed online with UO student access. (I found it by going to the UO Library site, searching for the title, which took me to ebrary.com, where it is available for download. Read it online, or offline with adobe digital editions reader.

← Older revision		Revision as of 23:06, 14 December 2015
Line 81:		Line 81:
	But what was evident to me towards the end of experiment was that there is no clear data for the mid-chaotic regime. This I think was caused by the creation of a cavity between the mirror and the worn APC face of the SL pigtail (about a meter shorter than the desired SL-mirror cavity). I base this on the fact that when I plugged the APC pigtail face through the 5m VOA and to the PD, I got an unwarranted external cavity with a frequency of 14MHz. This should not happen.		But what was evident to me towards the end of experiment was that there is no clear data for the mid-chaotic regime. This I think was caused by the creation of a cavity between the mirror and the worn APC face of the SL pigtail (about a meter shorter than the desired SL-mirror cavity). I base this on the fact that when I plugged the APC pigtail face through the 5m VOA and to the PD, I got an unwarranted external cavity with a frequency of 14MHz. This should not happen.

−	So, in summary, if you look at the highest regime of feedback that I tested, you should see evidence of a cavity disappearing as the laser power increases.	+	So, in summary, if you look at the highest regime of feedback that I tested, you should see evidence of a cavity disappearing as the laser power increases. However, if good chaotic feedback was attained in the lower dynamics is questionable, since the strong peaks seem to indicate a cavity that "locked" out these tiny signals.
		+
		+	Finally, here is a picture of the first chaos that I achieved, at about 45uW.
		+
		+	[[File:Chaos.jpeg\|450px]]

@@ Line 75: / Line 75: @@
 [[File:Externalcavity.JPG]]
-From my estimated 10m length of laser fiber, FC, VOA and mirror, and using n~1.5 for the glass fiber, it predicts of a cavity of ~10MHz
+From my estimated 10m length of laser fiber, FC, VOA and mirror, and using n~1.5 for the glass fiber, it predicts of a cavity of ~10MHz.
-From the plotted results of 317uW, you can easily see the sharp tiny peaks of high chaos begin to form, as the power level drops.  This is basically the effect of returning too much light into the laser cavity: instead of complicating things as it does at low feedback levels, it entirely wipes out the dynamics, and stabilizes the power.
+But when you look at 55uW, there is no real difference in the plots.  According to the theory, you should expect to see some route to quasiperiodicity (definite change in peak height), and then to chaos (sharp, even peaks).   From the plotted results of 317uW, you CAN easily see the sharp tiny peaks of high chaos begin to form, as the power level drops.  This is basically the effect of returning too much light into the laser cavity: instead of complicating things as it does at low feedback levels, it entirely wipes out the dynamics, and stabilizes the power.

← Older revision		Revision as of 22:50, 14 December 2015
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	Unfortunately, there were some complicating issues that make me wonder if I actually achieved chaos. From the 15uW frequency plot, you can see peaks spaced 10MHz apart. This indicates a cavity, which matches the calculated external feedback frequency for it.		Unfortunately, there were some complicating issues that make me wonder if I actually achieved chaos. From the 15uW frequency plot, you can see peaks spaced 10MHz apart. This indicates a cavity, which matches the calculated external feedback frequency for it.

		+	[[File:Externalcavity.JPG]]

		+	From my estimated 10m length of laser fiber, FC, VOA and mirror, and using n~1.5 for the glass fiber, it predicts of a cavity of ~10MHz

	From the plotted results of 317uW, you can easily see the sharp tiny peaks of high chaos begin to form, as the power level drops. This is basically the effect of returning too much light into the laser cavity: instead of complicating things as it does at low feedback levels, it entirely wipes out the dynamics, and stabilizes the power.		From the plotted results of 317uW, you can easily see the sharp tiny peaks of high chaos begin to form, as the power level drops. This is basically the effect of returning too much light into the laser cavity: instead of complicating things as it does at low feedback levels, it entirely wipes out the dynamics, and stabilizes the power.