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FAQs - frequently asked questions and answers
 
Questions about SAMs
>  Can I clean a dirty SAM surface?  
>  What is the main difference between glued and soldered SAMs?  
>  When I need an edge mounted SAM?  
>  Which type of SAM can I use in a Nd-doped ps laser at 1064 nm?  
>  Which type of SAM can I use in an Yb-doped fs laser around 1040 nm?  
>  Which type of SAM can I use in a ps fiber laser?  
>  Which type of SAM can I use in a fs fiber laser?  
>  Does the damage threshold in the spec sheets indicate the maximum mean power density?  
>  Do I need a SAM with sub-picosecond relaxation time for mode locking a fs laser?  
>  What can I do to avoid Q-switching?  
>  How can I check a fiber coupled SAM?  
 
  Questions about delivery and payment
>  How can I buy BATOP products from abroad?  
>  What is the delivery time for BATOP products?  
>  How can I pay for BATOP products?  
>  Can I pay with an other currency besides EURO?  
 
 
Answers about SAMs
>  Can I clean a dirty SAM surface? up
  Yes. The SAM surface can be cleaned by blowing off with a dry argon or nitrogen gas beam or also with ethanol or acetone using a soft lens tissue.
 
>  What is the main difference between glued and soldered SAMs?  
  The thermal resistance of soldered SAM chips is lower than of glued.  
 
>  When I need an edge mounted SAM?  
  In case of a folded beam using a focussing mirror to increase the power density on the SAM.  
 
>  Which type of SAM can I use in a Nd-doped ps laser at 1064 nm?  
  A SAM-1064-1-x or 1064-2-x.  
 
>  Which type of SAM can I use in an Yb-doped fs laser around 1040 nm?  
  A SAM-1040-1-x or 1040-0.7-x.  
 
>  Which type of SAM can I use in a ps fiber laser?  
  A resonant SAM with absorbance values between 20% and 50% depending on the fiber gain. Also a broadband antiresonant SAM can be used, but it has a larger saturation fluence.  
 
>  Which type of SAM can I use in a fs fiber laser?  
  An antiresonant SAM with absorbance values between 20% and 50% depending on the fiber gain.  
 
>  Does the damage threshold in the spec sheets indicate the maximum mean power density?  
  No, the damage threshold indicates the peak power density inside the laser cavity on the SAM.  
 
>  Do I need a SAM with sub-picosecond relaxation time for mode locking a fs laser?  
  No, for soliton mode locking the relaxation time can be up to about a factor of 40 longer than the needed pulse width. See J. Opt. Soc. Am. B/ Vol. 16, No. 1/January 1999 p. 46 -56.  
 
>  What can I do to avoid Q-switching?  
 

If you have Q-switching instead of cw mode locking, the power density on the SAM is probably too low. You have to increase the power density above the Q-switching threshold to get cw mode-locking and to avoid SAM surface damage. The condition to get stable cw mode locking can be written after Hönninger et. al., J. Opt. Soc. Am. B/ Vol. 16, No. 1/January 1999 p. 46 -56 as

Formula cw mode locking condition 		 
  with EP    - intracavity pulse energy  
  Esat,L - saturation energy of the laser gain (Fsat,L . Aeff,L)  
  Esat,A - saturation energy of the absorber (Fsat,A . Aeff,A)  
  DR    - modulation depth of the saturable absorber mirror (SAM)  
 
>  How can I check a fiber coupled SAM?  
 

The best way is the measurement of the spectral low intensity reflectance using the setup shown below.

Test setup for fiber coupled SAM 		 
 
 
 
Answers about delivery and payment
>  How can I buy BATOP products from abroad? up
  You can buy our products direct from BATOP GmbH in Germany or via our distributors.
 
>  What is the delivery time for BATOP products?  
  The listed products on our internet pages are in stock if not otherwise indicated. The typical delivery time is one week.  
 
>  How can I pay for BATOP products?  
  You can pay by wire transfer, check, and credit card (VISA or MASTER).  
 
>  Can I pay with an other currency besides EURO?  
  Yes, you can pay with any currency. Please ask for a quotation in foreign currency.  
 
 
 
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