Widely tunable laser frequency offset lock with 30 GHz range and 5 THz offset

We demonstrate a simple and versatile method to greatly extend the tuning range of optical frequency shifting devices, such as acousto-optic modulators (AOMs). We use this method to stabilize the frequency of a tunable narrow-band continuous-wave (CW) laser to a transmission maximum of an external Fabry-Perot interferometer (FPI) with a tunable frequency offset. This is achieved through a servo loop which contains an in-loop AOM for simple radiofrequency (RF) tuning of the optical frequency over the full 30 GHz mode-hop-free tuning range of the CW laser. By stabilizing the length of the FPI to a stabilized helium-neon (HeNe) laser (at 5 THz offset from the tunable laser) we simultaneously transfer the similar to 1 MHz absolute frequency stability of the HeNe laser to the entire 30 GHz range of the tunable laser. Thus, our method allows simple, wide-range, fast and reproducible optical frequency tuning and absolute optical frequency measurements through RF electronics, which is here demonstrated by repeatedly recording a 27-GHz-wide molecular iodine spectrum at scan rates up to 500 MHz/s. General technical aspects that determine the performance of the method are discussed in detail. (C) 2013 Optical Society of Americ

- v=0 vibrational overtone in cold trapped HD+

We report the observation of the hitherto undetected v'=8a dagger v=0 vibrational overtone in trapped HD+ molecular ions, sympathetically cooled by laser-cooled Be+ ions. The overtone is excited using 782 nm laser radiation, after which HD+ ions in v=8 are photodissociated by the 313 nm laser used for Be+ cooling. The concomitant loss of HD+ is detected by the method of secular excitation (Roth et al. in Phys. Rev. A. 74:040501(R), 2006). We furthermore present details of the experimental setup, and we show that results from spectroscopy of v'=8a dagger v=0 overtones in combination with accurate ab initio calculations may yield a new value for the proton-electron mass ratio with an accuracy of order 1 ppb

Self-efficacy and emotional adjustment as precursors of smoking in early adolescence

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Heterogeneity of girls' consensual popularity: Academic and interpersonal behavioral profiles

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Emotional Separation, Autonomy in Decision-Making, and Psychosocial Adjustment in Adolescence: A Proposed Typology

Adolescence is critical for learning autonomous behavior; however, little research is available on the most appropriate balance of the emotional and behavioral dimensions of autonomy for psychosocial adjustment during this period. In this study we present a novel autonomy typology that combines both these aspects, which can be implemented as autonomy in decision-making and emotional separation. Specifically, examined age differences in emotional separation and autonomy in decision-making during adolescence. We also assessed differences in psychosocial adjustment associated with profiles of autonomy typology, sex, and age. The participants were 567 adolescents (296 males and 271 females), aged between 12 and 18 years (M = 14.48; SD = 1.69), recruited in Spanish high schools. Each participant filled out questionnaires on identity commitment, self-esteem, emotional separation and autonomy in decision-making. The results showed that the most advantageous autonomy profile is ‘autonomous in decisions’ (those showing low emotional separation combined with autonomous behavior in decisions) which was associated with higher levels of self-esteem and occupational and ideological identity commitment. In addition, we also concluded that the balance of autonomy affects adjustment throughout adolescence, although early adolescence may be an especially critical period