Beijing Photek S&T Development Co., Ltd. (北京福托科技开发有限责任公司 Běijīng Fútuō Kējì Kāifā Yǒuxiàn Zérèn Gōngsī), also known as Quadimension (平行四界 Píngxíng Sì Jiè), is a company that consists of Chinese producers who originally created and distributed the Quadimension album series which mainly featured a selection of Chinese VOCALOIDs. They collaborated with Shanghai HENIAN Information Technology Co. Ltd. to create a voicebank for their mascot and first Chinese VOCALOID, Stardust.
Quadimension began as a group that created doujinshi albums under the same name. These albums mainly featured Luo Tianyi, but began adding more VOCALOIDs since Quadimension 3's release in 2015 . Quadimension collaborated with a variety of producers who became members of the group though not every person stayed permanently.
In the album pamphlets, their mascot appeared in some of the artwork. This mascot was known as Quadimensionko in the past but eventually became their first VOCALOID, Stardust. Quadimension commissioned Shanghai HENIAN to create a VOCALOID4 voicebank for her while they handled her character and marketing rights. She became the first entry of the Voicebank Customize Project.
Later, Beijing Photek was adopted as their company name. This was to keep the VOCALOID development and marketing business separate from the producer circle and to sound more professional.