PHYSICAL REVIEW A VOLUME 46, NUMBER 1 1 JULY 1992 Laser ynamxcs of type-I ' t an ermittency D. Y. Tang, M. Y. Li an e(; nlsehe Bundesanstalt 3300B ei (Received 10 F b raunsch hei e ruary 1992) eig, Germany We re ort p the experimental observati We show that b y anal zin o servation of an interm'tt can th ' t 1 i ent route t g e-mode ring laser. ynamics. ver e, serve intermitten ency PA ACS number(s): 42. 50 L, c, 05. 45. +b Among the three well-known route d t d ynamical s stem as een studied extensiv s via mittency is characteriz d tl i t tdb c p e y chaotic "burst h b i 11 e. . enta y observed in ica systems 7 — 9 . g. , in hydrodynam' 1 several systems [o- ] in nonlinear oscillator es a i ization of o jntermjttency h f' o' td 'th M}. dl- 1 II sa e-node bifurca ' i ency with a sub dt -III ' h furcation. wit asubc ' ' ' - u ing i ritical period-doubling i- Interm' ermittency routes to chaos of d' yp cle ve in optical systems. In h otd h type-III interm'tt e t e experimen i ency route to chaos tal observation of pumped far-infrared 1 e aser [16~. Sac " an c aos in an opticall G"b 1 h d h r e t e observation o 7 yp- [ ]. -I' t tt h tems so far. observed in optical sys- We report here p ere the experimental ob yp- 'n an optically pum ed P ' 3 v td o ' 'h at t e observed d n ' ' in- ' ~ arison with the usual d [18]. B p y using the ex manner, we find good a r in a 1 1 d h termittency. s an the chara h acteristics of type-I in- The experimental setup used is an NH f - f d ring laser as u e -pm wavelength and is 81- D d' h ' go th op ti kinds of chaos have b g conditions, different them ave een observed on t c aos [20,21] and t e- Lo t -t h ing is easy to chan e h e experimentall the [16] B y e resonator detun- ator detuning was used ange, in the present expenment the reso- ot t er parameters were fixed. as used as the control parameter and all A typical observation at a gas ress of3W/ c, t e resonator detunin g. g e uning, the laser laser pulses periodically. p d We find that this kin sma l f is in of intermittenc escnbed occurs t na or etunin and ' g the whole proces a resonator detun' ess one for which th e period-doublin uning larger than th n e g o o[] e resonator detunin g ic intermittent ch this intermittent ch c aos Fig. 1(c) occurs c aos consequentl d', e n y isappears, and the (a) -; :IIIIIIhIhIIIIII IIIiIIhIhIIII IIII Ih C I 20 40 60 80 80 100 120 140 Time (ps) FIG. 1. Tim ime dependence of the 1aser emissi d i ' h d NH 3g p I cm. From (a) to (c) the r , pump in- creased. o c t e resonator detuning is de- As the re sonator detuning decreases t this riodi lsi b i to 1 b 1""' "'"'""'""""'"'"'" ' Th i t ti b ions ecome more fre ~ ~ tor detuning is furth requent as the resona- t ' ' r er reduced, and the od (1 i 1 th ) f Q q s o the laser chaos. e expected for an intermittent route to Som ome features of this inter i erent from other ics are p [— a e oscillations are int by h b f 1 s o ar ger eaks om ofh NH1 3 aser is interru ted sing dependent on the co age urations of th he laminar lengths are stro e control parameter len gths are small and the d n parameter, the Quctuatio ic. e ynamics is almost uasi erio- 46 676 1992 The American Ph can ysical Society