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We develop a Sagnac-type source of ultrabright, non-degenerate,polarization-entangled photon pair that is highly stable and compactsimultaneously. We use a $20~\text{mm}$ long PPLN bulk crystal which, uponpumping continuously with $532~\text{nm}$ wavelength, producespolarization-entangled photon-pairs of $785~\text{nm}$ signal and$1651~\text{nm}$ idler wavelengths via the type-0 spontaneous parametricdown-conversion (SPDC) process. All optical components used in the setup areoff-the-shelf components, readily available commercially; hence, nocustom-designed or costly multi-wavelength polarization optics are required. Atthe same time, long-term phase stability is achieved without any additionalactive stabilization; due to the geometry of our Sagnac-type design. We alsoreport one of the highest brightness of non-degenerate polarization-entangledphoton pairs available in the literature. Even with a very low pump power of$0.034~\text{mW}$, we detect a coincidence rate of $(6.96\pm 0.03)\times10^{4}$entangled pairs/sec/mW (averaged over three polarization-basis measurements:H/V, D/A, and R/L basis). The source's brightness is calculated to be $(6.17\pm0.04)\times10^{6}$ entangled pairs/sec/mW for the signal line width of$0.4~\text{nm}$. From the raw coincidence counts (without any backgroundcoincidence correction), the fidelity of the entangled state is measured to be$(96.72\pm 0.01)\%$ with a concurrence of $(94.68\pm 0.20)\%$. Bell-CHSHinequality violation is reported as $S=2.71\pm 0.06$.

Ultrabright Sagnac-type source of non-degenerate polarization-entangled photon pairs using only off-the-shelf optical components