Let $P\left(1,\mathrm{}7,\mathrm{}\sqrt{2}\right)$ be a point and the equation of the line $L$ is $\frac{x-1}{\sqrt{2}}=\frac{y-7}{1}=\frac{z-\sqrt{2}}{-1}$. If $PQ$ is the distance of the plane $\sqrt{2}x+y-z=1$ from the point $P$ measured along a line inclined at an angle $60°$ with $L$, then the length of $PQ$ is