Triangular optical-trap response
= Triangular optical-trap response
{title2=$f_p/f_c$}
A triangular localized <potential energy> has forces $+F$ behind and $-F$ ahead of the trap centre. With $v_c=F/\zeta=Lf_c$, $\alpha=2X_0/L$ and $\beta=f_T/f_c$, its circular response is $f_p/f_c=\alpha\beta/(\beta^2-1+\alpha)$ for $\beta>1$. A trapped particle has $f_p/f_c=\beta$ for $0\le\beta\le1$, interpreting the discontinuous <force> at the cusp by a sticking or rounded-well limit.