Out of curiosity, and just to clarify the nomenclature, @3:29 when discussing the waveguide modes, is this academically correct to synonymize that with "guided modes" &/ propagation modes or the latter refer to a different concept in the EM theory?
For waveguides, I think it is most proper to call them guided modes. I am not entirely sure what a "propagating mode" is. Maybe in a something like a photonic crystal with a band gap you would have propagating modes and cutoff modes. That is just a guess as to what is meant by "propagating mode." If it came up in the context of waveguides, I would probably interpret that is the same as guided mode.
@@empossible1577 Thanks for the clarification, I read thru your reply and I think you're right about not having heard much on "propagating modes" in opposed to a "guided mode" ... most probably was a misnomer from a memory of a conversation that I had a few years back with my graduate advisor in an around the topic. Would you comment a bit on the "cut-off modes" in a photonic crystal? or point me to one of your lectures in which you discuss them. Thanks,
@@rattinyou Modes that are cutoff in waveguides, photonic crystals, or even free space waves (think total internal reflection) all occur with the same physics and properties. Those modes still exist. It is just that they decay quickly. If your photonic crystal slab is thin enough and the cutoff mode does not decay all the way, it will excite a propagating mode on the other side. This is called tunneling. It happens in waveguides, free space waves, and electrons in semiconductors. I don't have much information specifically on the cutoff modes, but all of the advanced topics are covered in my 21st Century Electromagnetics class. here is a link: empossible.net/academics/21cem/ You will find photonic crystals in the Engineered Materials topic. I highly recommend going through Topic 4 first.
great video
Amazing, one word! I'm a senior photonics staff and still benefit from your lectures!
Glad they are helping you!
Thank you so much for sharing. Greetings from Panama 🇵🇦
Hello Panama!! Great to have you here!
very great video
Out of curiosity, and just to clarify the nomenclature, @3:29 when discussing the waveguide modes, is this academically correct to synonymize that with "guided modes" &/ propagation modes or the latter refer to a different concept in the EM theory?
For waveguides, I think it is most proper to call them guided modes. I am not entirely sure what a "propagating mode" is. Maybe in a something like a photonic crystal with a band gap you would have propagating modes and cutoff modes. That is just a guess as to what is meant by "propagating mode." If it came up in the context of waveguides, I would probably interpret that is the same as guided mode.
@@empossible1577 Thanks for the clarification, I read thru your reply and I think you're right about not having heard much on "propagating modes" in opposed to a "guided mode" ... most probably was a misnomer from a memory of a conversation that I had a few years back with my graduate advisor in an around the topic. Would you comment a bit on the "cut-off modes" in a photonic crystal? or point me to one of your lectures in which you discuss them.
Thanks,
@@rattinyou Modes that are cutoff in waveguides, photonic crystals, or even free space waves (think total internal reflection) all occur with the same physics and properties. Those modes still exist. It is just that they decay quickly. If your photonic crystal slab is thin enough and the cutoff mode does not decay all the way, it will excite a propagating mode on the other side. This is called tunneling. It happens in waveguides, free space waves, and electrons in semiconductors.
I don't have much information specifically on the cutoff modes, but all of the advanced topics are covered in my 21st Century Electromagnetics class. here is a link:
empossible.net/academics/21cem/
You will find photonic crystals in the Engineered Materials topic. I highly recommend going through Topic 4 first.
@@empossible1577 Thanks Prof. Rumpf, this was quite helpful, I'll follow through with your suggestions.
Thank you
You are welcome!