Patent ID: 7013069

Claim:
An optical module for separating channel signals with high isolation, the optical module comprising; an optical lens having a facet to receive a multiplexed input signal at a small incident angle, the multiplexed signal including at least a signal at wavelength λ1 (hereinafter “the λ1 signal”) and another signal at wavelength λ2 (hereinafter “the λ2 signal”); a first filter configured to reflect only the λ1 signal and transmit signals at wavelengths other than wavelength λ1, the optical lens collimating the multiplexed signal onto the first filter at a small incident angle from a first optical path therein, the λ1 signal reflected from the first filter propagating along a second optical path in the optical lens, wherein the facet of the optical lens is oriented non-congruently with a corresponding facet of the first filter with respect to an optical axis of the optical lens, and a second filter, configured to reflect only the λ2 signal and transmit signals at wavelengths other than wavelength λ2, receiving the signals at wavelengths other than wavelength λ1 from the first filter, the second filter reflecting the λ2 signal therein to a designated device and transmitting remaining signals at wavelengths other than wavelength λ2, wherein the λ1 signal and the λ2 signal are highly isolated from each other by the small incident angle to the first filter, and a frequency response of the first filter depends on an incident angle thereto; a dual fiber pigtail including a first fiber core to couple the multiplexed signal to the optical lens and a second fiber core to receive the λ1 signal from the second optical path; and a third filter attached to a facet of the second fiber core to block any portion of the λ2 signal that may have been reflected by the first filter, wherein the third filter has a frequency response reciprocal to that of the first filter.