The profile that you describe is not TEM01 (a double D pattern) but TEM01* or the donut mode.  It is a superposition of TEM10 and TEM01.  It can be linearly polarized (vertical or horizontal) or radially polarized or tangentially polarized.

Lauren M. Peterson, PhD     Lead Physicist - Photonics    
Michigan Research & Development Center  
General Dynamics - Advanced Information Systems;   Integrated Space Systems 
1200 Joe Hall Dr.,  P.O. Box 990       Ypsilanti, MI  48197    
734-480-5303       -480-5252 FAX      ISS-SIS-ATD-EPA
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      Demetrius Ypsilanti fought in the Greek war for independence against the Ottoman Empire and led the culminating Battle of Petra in 1829.


-----Original Message-----
From: Confocal Microscopy List [mailto:[log in to unmask]] On Behalf Of Jerry (Gerald) Sedgewick
Sent: Thursday, August 20, 2009 3:01 PM
To: [log in to unmask]
Subject: Re: laser profiles

I have been requested to provide a non-gaussian profile for the laser 
output on our Ti:Sapphire laser that is used on our custom built 
multiphoton devices.   This profile--apparently more of an 
annulus--works best for obtaining SHG on nano-sized features introduced 
onto metal surfaces.  The profile is referred to as TEM10 (versus TEM00, 
which is a gaussian profile). 

Since I am hoping to add an additional laser to the system, my desire is 
to provide a laser system in which either the TEM00 or TEM10 profile can 
be chosen, if this is even a possibility. 

Barring that, can the TEM10 profile be used on standard biological 
samples for both SHG and standard excitation of fluorophores, or will 
the profile affect the results (e.g., will resolution or some other 
characteristic change)?

If anyone has had experience with the TEM10 profile, I'd appreciate 
feedback!

Jerry Sedgewick
Program Director
Biomedical Image Processing Lab
University of Minnesota