We report a self-phase-locked and degenerate backward wave optical parametric oscillator (BWOPO) generating a counterpropagating signal and an idler in the spectral band of optical communication. The device is based on a periodically poled Rb-doped KTiOPO4 crystal with a poling period of 433 nm. To the best of our knowledge. this is the shortest quasi-phase matching period reported in... https://leoners.shop/product-category/bed-frame/