Angle limiting filter include a glass substrate including a plurality of non-transparent glass-ceramic regions and a plurality of substantially optically transparent regions in an alternating arrangement. The non-transparent glass-ceramic regions and the substantially optically transparent regions are formed from the same glass composition. A method for forming the angle limiting filter includes irradiating a glass substrate with an ultra-violet radiation source through a patterned photomask to selectively irradiate regions in the glass substrate. The method also includes heating the glass substrate thereby transforming the irradiated regions into non-transparent glass-ceramic regions and forming an alternating arrangement of non-transparent glass-ceramic regions and substantially optically transparent regions in the glass substrate. Electronic devices, including pulse oximeters, including the angle limiting filter are also described.一種角度限制過濾器包含玻璃基板，該玻璃基板包含以交替方式排列的複數個不透明玻璃陶瓷區域及複數個實質上光學透明的區域。不透明玻璃陶瓷區域及實質上光學透明的區域係由相同的玻璃組合物形成。本案描述了一種用於形成角度限制過濾器的方法，該方法包含以下步驟，以紫外線輻射源通過圖案化光罩照射玻璃基板，以選擇性地照射該玻璃基板中的區域。該方法亦包含以下步驟：加熱玻璃基板從而將被照射區域轉變成不透明玻璃陶瓷區域，並在玻璃基板中形成以交替方式排列的不透明玻璃陶瓷區域及實質上光學透明的區域。本案亦描述了包含角度限制過濾器之電子裝置，包含脈搏血氧儀。
