To expand its product line and increase its manufacturing capability, Alliance Fiber Optic Products Inc. (AFOP) of Sunnyvale, Calif., has agreed to acquire most of the assets of Ritek Corp.'s Photonics Div. and to assume certain liabilities in exchange for up to 1.7 million shares of common stock. AFOP, a supplier of fiber optic components, subsystems and integrated modules for the optical network equipment market, may use the division's facility in Hsinchu, Taiwan, for two years at no extra cost. Ritek, whose photonics business includes active devices and fiber array, dense wavelength division multiplexing and planar lightwave circuit technologies, will pay AFOP $1.5 million in cash. With the acquisition of Ritek's products and customer base for the growing access and fiber-to-the-customer markets, AFOP intends to strengthen its presence in Asia.