If optical product makers build 3D sensors into mobile phones, they could attract Apple and other smartphone makers, emerge as potential customers, and drive Finisar and Lumentum's sales even higher. This could also be a great business opportunity. However, an analyst cautions that it remains difficult to nail down.

Finisar has recently joined Lumentum Holdings in developing 3D and optical sensors. Lumentum Holdings manufactures and sells optical and photonic products --- operating in two segments, namely commercial lasers and optical communications. Phone companies such as AT&T and Verizon Communications and internet firms such as Amazon and Facebook have been the biggest traditional customers of this fiber-optic parts makers since they all need faster communications in data centers.

But according to William Blair analyst Dmitry Netis' statement in a mid-December report, these two investors should be cautious and should not get ahead of themselves even if the 3D sensing opportunity appears very real. Yes, the said opportunity could spur in late 2017 and further into 2018. However, the whole ecosystem must be established first. A good chance of it coming together can be foreseen if top smartphone manufacturers like Apple would be behind this initiative, although it would be difficult to nail down as of the moment.

There's also a possibility that Apple's iPhone 8 would be integrated with 3D photography, which is expected to be released in late 2017. But as what some analysts also say, laser-based 3D sensor devices would likely have other applications.

According to Piper Jaffray's statement in September, Lumentum Holdings is developing a 3D sensing device for an unnamed smartphone maker. Lumentum's forerunner, JDS Uniphase, developed the 3D sensor technology for Microsoft's Kinect motion-gaming system, which was released in 2010 as part of the Xbox 360 gaming bundle.