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  *Introduction:*Since the invention of the separated-ﬁeld 
  technique [1], it has played an important role in the ﬁeld of 
  precision spectroscopy due to its linewidth narrowing eﬀect 
  via multiple coherent interaction. Atomic clocks based on 
  this technique have greatly extended our ability for frequency 
  measurement, further, almost all the atom interferometers are 
  based on this technique [2]. 
  
  cus on the stimulated emission spectrum via multiple coher- 
  ent interactions inside the cavity. We ﬁnd this Ramsey laser 
  can provide a stimulated-emission spectrum with a linewidth 
  much narrower than that of any conventional optical Ramsey 
  seperated-ﬁeld spectroscopy, which is commonly applied in 
  optical atomic clock. Our results also show that a subnatural 
  linewidth spectroscopy, superior to any other available subnat- 
  ural spectroscopy technique at present [3–10], can be reached 
  by this kind of laser, if a suitable atomic level structure is cho- 
  sen. Thus, this method can provide an eﬀective subnatural 
  spectroscopy, and the possibilities for the new optical clock 
  scheme [15] and atom interferometers [2]. 
  
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