- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Effect of cold finger temperature on optical pulse modulation characteristics in a 2.59 terahertz quantum cascade laser
摘要： Terahertz (THz) frequency sources such as quantum cascade lasers (QCLs) offer a variety of new applications in far-infrared frequency bands. For better understanding of their behavior, a device-specific modeling approach is used to predict the optical output power under current modulation and chip temperature. This letter reports the numerical simulation of gain switching to evaluate temperature dependence for short pulse generation in QCLs. Modified rate equations are used for self-consistent computation of emitted THz optical power from QCLs. The device emits at 116 μm and is driven by various inputs such as haversine, tangential hyperbolic and square electrical pulses. From the simulation it is evident that the square input pulse requires the least magnitude current (0.83 A) at 15 K to generate pulses with minimum full width half maximum (FWHM). Moreover, when the peak amplitude of the square input signal is 1.01 A, it generates optical pulses with the least FWHM of 19.42 ps at 45 K. In the case of the haversine input with peak amplitude of 1.8A, a peak power of 27.86 mW is generated at 15 K.
关键词： cold finger temperature,rate equation model,numerical simulation,quantum cascade lasers,full width half maximum,gain switching,optical short pulses
更新于2025-09-23 15:19:57
-
Performance analysis of direct detection optical OFDM systems
摘要： Orthogonal frequency division multiplexing (OFDM) is a multicarrier modulation technique, in which the data information is carried over many lower rate subcarriers. This technique is started effectively using in both line communication and wireless communication systems. This modulation technique has been actively started in the field of light wave communication called optical OFDM (OOFDM) system. OOFDM is a multicarrier modulation technique; it is used to overcome the problem of inter-symbol interference due to the chromatic dispersion and polarization mode dispersion of the fiber channel. In this paper, we have done simulation on direct detection optical OFDM (DDOOFDM) system with data rate of 10Gbps and measuring performance analysis of DDOOFDM system with respect to the received optical power and various full width half maximum value of the continuous wave laser source. This analysis is simulated using RSOFT Design Group OptSim Version-5.2.
关键词： Mach-Zehnder Modulator (MZM),Coherent Detection Optical OFDM (COOFDM),Optical Band Pass Filter (OBPF),Optical Single Sideband (OSSB),Full Width Half Maximum (FWHM),Direct Detection Optical OFDM (DDOOFDM)
更新于2025-09-04 15:30:14