How does a bended circular waveguide transform TE and TM modes?

[Ricvil]

http://ir.hfcas.ac.cn/bitstream/334002/12022/1/Mode%20converters%20for%20generating%20the%20HE%2011%20%28gaussian%20like%29%20mode%20from%20TE%2001%20in%20a%20circular%20waveguide.pdf
In the above article, the mode coupling theory shows how a bended circular waveguide transforms a TE01 mode into a TM11 mode.
Of course, always will be spurious modes in the process.
My questions are about :
1- By temporal reverse symmetry , the same bended pipe can transform both TE into TM and TM into TE modes?
2-By Parity/mirror symmetry, if one cuts the same converter at it's half length and close one of the ends with the same metal of the waveguide, then if one inject a TE mode at the other open end, one gets a TM reflected mode?

 

[tech99]

http://ir.hfcas.ac.cn/bitstream/334002/12022/1/Mode%20converters%20for%20generating%20the%20HE%2011%20%28gaussian%20like%29%20mode%20from%20TE%2001%20in%20a%20circular%20waveguide.pdf
In the above article, the mode coupling theory shows how a bended circular waveguide transforms a TE01 mode into a TM11 mode.
Of course, always will be spurious modes in the process.
My questions are about :
1- By temporal reverse symmetry , the same bended pipe can transform both TE into TM and TM into TE modes?
2-By Parity/mirror symmetry, if one cuts the same converter at it's half length and close one of the ends with the same metal of the waveguide, then if one inject a TE mode at the other open end, one gets a TM reflected mode?

HE11 is not the same as TM11. However, I am sure the mode transition must operate in both directions by reciprocity considerations, and also in the reflection method you describe.

 

[Ricvil]

HE11 is not the same as TM11. However, I am sure the mode transition must operate in both directions by reciprocity considerations, and also in the reflection method you describe.

Thank you for the answer.
About the HE11 in the article, it is obtained from TM11 resulting from the first stage of conversion, TE01-TM11-HE11.

 

[tech99]

Thank you for the answer.
About the HE11 in the article, it is obtained from TM11 resulting from the first stage of conversion, TE01-TM11-HE11.

Thanks for the clarification.
In the case of the reflection-type mode converter. I cannot see how you can easily separate the two modes present at the port.