Single-mode giga-hertz optical pulses generated by a self-modulation of the relaxation oscillation frequency in a semiconductor laser with subharmonic polarization-rotated optical feedback

All-optical controlled switching between time-periodic square waves in diode lasers with delayed feedback

“…Among the diverse setups studied experimentally, the laser subject to polarization rotated optical feedback (PROF) is particularly attractive [4][5][6][7][8][9][10]. It has found a variety of applications stemming from alloptical production of high frequency pulses [11] and from its chaotic behavior for random bit generation [12]. Moreover, its rate equations can be analyzed in more detail than the traditional single polarization feedback [7].…”

Asymmetric square-waves in mutually coupled semiconductor lasers

“…10,11 In addition, there are a variety of useful applications involving the all-optical production of high-frequency optical pulses. 12 The research presented in this paper extends the investigation of polarization-rotated systems to a system of two lasers that are mutually coupled via polarization-rotated optical injection. Complex dynamics are present in such a system, but we also find solutions of stable, regular square pulses.…”

Ultrashort pulse generation in a semiconductor laser with strong coherent optical feedback

“…The behaviour of single mode semiconductor lasers with coherent external optical feedback can be described using the following equations which are based on the wellknown Lang and Kobayashi (L-K) equations [24,25]. Note that the L-K equations can also be modified to describe single mode semiconductor lasers with incoherent feedback which model has been used and tested for many years to study the generation of single wavelength picosecond pulses [16,26,27].…”

“…In this paper, a novel technique is proposed to generate ultrashort pulses using a semiconductor laser (SL) with external optical feedback (EOF). Comparing to other techniques, an SL with EOF requires neither external modulation nor saturable absorbers and the pulses generated have a single centre wavelength which are important in several applications, such as dense wavelength-division multiplex (DWDM) communications [16] and multi-photon imaging for clinical diagnostics [17]. With the aid of rate equations, we identify a region where the ultrashort pulses are generated by exploring basic parameters of the SL with EOF, and specifically the laser injection current, the external cavity length and the feedback strength.…”