## 1 Introduction  
Long wavelength semiconductor laser diodes have been an important technology in recent years, because of their major role in optical communications [1]. These lasers emit at wavelengths near the infrared band, and the InGaAs material system has shown promise as an active layer candidate for realizing wavelengths beyond 1 \(\upmu\)m. Because the large lattice mismatch between InGaAs and GaAs substrates limits the layer thickness and heterointerface smoothness, several studies have been performed to improve the interface roughness and crystal quality. [PERSON] et al. improved the quality of the GaAs/InGaAs interface using short annealing steps at various growth temperatures [2]. [PERSON] et al. demonstrated the possibility of avoiding strain accumulation in InGaAs layers using a gas-switching technique during growth [3]. In order to achieve a longer excitation wavelength, it is necessary to increase the indium (In) content in InGaAs QWs. However, a high content of In tends to cause a significant lattice mismatch between the wells and barriers. Lattice-mismatched heteroepitaxy is always accompanied by the generation of strain and dislocations, which degrade the device performance [4]. In order to reduce or eliminate strain accumulation and the formation of defects in QWs, tensile-strain GaAsP barrier layers have been employed to compensate for the compressive strain in the InGaAs QW layer. Compressive strain in the well and tensile strain in the barrier can offset each other during epitaxial growth, which reduces the formation of defects, such as dislocations [5]. Therefore, radiative recombination and surface roughness can be improved. However, the precise strain-balanced condition is not straightforward, and the mismatch strain is unavoidable. The growth of high quality InGaAs/GaAsP QWs is vital for realizing high performance devices. [PERSON] et al. found that a reduction in the growth temperature yielded highly strained epitaxial layers with decent optical properties presumably owing to the reduced formation and propagation of dislocations [6]. [PERSON] et al. studied the influence of different compositions of phosphorus in the barrier layer on the production of a high quality and smooth heterointerface of InGaAs/GaAsP QWs [7]. [PERSON] et al. investigated the influence of growth temperature on interfacial quality of InGaAs/GaAsP multiple quantum wells [8]. Therefore, the optimization of crystal growth conditions is crucial to facilitate the production of high-performance devices. Substrate misorientation is known to be crucial for developing high-efficiency solar cells and high-performance QW diode lasers [9]. However, the correlation between the structural and optical properties of InGaAs QWs and GaAs substrates with different misorientation angles has not yet been thoroughly investigated. [PERSON] et al. investigated the influence of a tilted substrate on the photoluminescence, mismatch, doping, thickness, and morphology of GaInP QWs and found that the 15\({}^{\circ}\) substrate was a suitable choice for use in a red light waveband laser diode wafer [10]. [PERSON] et al. studied the influence of growth interruption and substrate misorientation on the optical and heterointerface properties; the use of the growth interruption technique during growth resulted in the 2\({}^{\circ}\) substrate being preferred for the growth of InGaAs/GaAs QWs [11]. They mainly explored the effect of epitaxial growth conditions on the structure of materials with little lattice mismatch on misoriented substrate. However, there are few studies about the effect of substrate misorientation on QWs with large lattice mismatch. The use of vicinal substrates for growing InGaAs/GaAsP QWs has become technologically significant because they result in improved optical properties [9]. However, the correlation between the structural and optical properties of In-rich InGaAs QWs and GaAs substrates with different misorientation angles has not been elucidated.