Q-switched single frequency monolitic, non planar ring laser

摘要

Monolithic, non-planar, diode laser-pumped, single frequency Q-switched ring laser has a ring laser crystal (2) with three or more total reflection faces (B, C, D) and a dielectric-coated face (A) as input and output mirror (8), the crystal (2) causing reciprocal and non-reciprocal rotation of the laser light polarisation direction by means of non-planar beam passage and by means of the Faraday effect in a permanent magnetic field (16), respectively. The novelty is that (i) a switching crystal of suitable refractive index is provided and can be advanced up to a distance of about one laser radiation wavelength from one of the total reflection faces (B, C, D), for outward coupling of the evanescent wave field, or retracted for laser pulse generation; (ii) the ring laser crystal (2) consists of a laser material having saturable losses at the laser transition (laser emission wavelength); (iii) the ring laser crystal consists of a crystal of active laser material and another crystal of a saturable absorber material; or (iv) the ring laser crystal (2) consists of an active laser material crystal provided with a saturable absorber material layer (40) on at least one surface (A-D). Preferably, the active laser material in the lasers (i), (iii) and (iv) is Nd:YAG, Yb:YAG or Nd:LSB; the active laser material in lasers (iii) is Cr,Nd:YAG, Cr,Yb:YAG or Cr,Nd:LSB; and the saturable absorber material in lasers (iii) and (iv) is Cr4+:YAG.