Limits...
Optimizing SOI slot waveguide fabrication tolerances and strip-slot coupling for very efficient optical sensing.

Passaro VM, La Notte M - Sensors (Basel) (2012)

Bottom Line: In particular, we have focused on Silicon On Insulator (SOI) technology, representing the most popular technology for this kind of devices, simultaneously achieving high integration capabilities, small dimensions and low cost.An accurate analysis of single mode behavior for high aspect ratio slot waveguide has been also performed, in order to provide geometric limits for waveguide design purposes.Finally, the problem of coupling into a slot waveguide is addressed and a very compact and efficient slot coupler is proposed, whose geometry has been optimized to give a strip-slot-strip coupling efficiency close to 100%.

View Article: PubMed Central - PubMed

Affiliation: Dipartimento di Elettrotecnica ed Elettronica, Politecnico di Bari, Bari, Italy. passaro@deemail.poliba.it

ABSTRACT
Slot waveguides are becoming more and more attractive optical components, especially for chemical and bio-chemical sensing. In this paper an accurate analysis of slot waveguide fabrication tolerances is carried out, in order to find optimum design criteria for either homogeneous or absorption sensing mechanisms, in cases of low and high aspect ratio slot waveguides. In particular, we have focused on Silicon On Insulator (SOI) technology, representing the most popular technology for this kind of devices, simultaneously achieving high integration capabilities, small dimensions and low cost. An accurate analysis of single mode behavior for high aspect ratio slot waveguide has been also performed, in order to provide geometric limits for waveguide design purposes. Finally, the problem of coupling into a slot waveguide is addressed and a very compact and efficient slot coupler is proposed, whose geometry has been optimized to give a strip-slot-strip coupling efficiency close to 100%.

No MeSH data available.


Related in: MedlinePlus

Sensitivity (blue curve) and Γc (green curve) versus ϑ (a), tox (b), t2 (c) and tair (d), for W = 155 nm, g = 120 nm and H = 400 nm.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3376618&req=5

f11-sensors-12-02436: Sensitivity (blue curve) and Γc (green curve) versus ϑ (a), tox (b), t2 (c) and tair (d), for W = 155 nm, g = 120 nm and H = 400 nm.

Mentions: Since ϑ = 6° is a practically achievable value for SOI technology [9,17,18], parameters g = 120 nm, W = 155 nm and H = 400 nm are found to be the optimal choice, simultaneously achieving best fabrication tolerances with respect to sensitivity and single mode behavior. In fact, S = 0.92 has been calculated, showing a very low dependence with respect to both H and W. Then, practical advantages cannot be reached with an increase of W or H, without compromising the single mode behavior. On the other hand, this optimal choice guarantees a large tolerance for the silicon wires width, exhibiting a single mode behavior for W < 200 nm. This is a very important issue, due to the fact that W is dependent on both photo-lithography and etching processes, differently from the height of the slot waveguide. Figure 11(a–d) show the variation of both sensitivity and power confinement factor with respect to several technological parameters.


Optimizing SOI slot waveguide fabrication tolerances and strip-slot coupling for very efficient optical sensing.

Passaro VM, La Notte M - Sensors (Basel) (2012)

Sensitivity (blue curve) and Γc (green curve) versus ϑ (a), tox (b), t2 (c) and tair (d), for W = 155 nm, g = 120 nm and H = 400 nm.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3376618&req=5

f11-sensors-12-02436: Sensitivity (blue curve) and Γc (green curve) versus ϑ (a), tox (b), t2 (c) and tair (d), for W = 155 nm, g = 120 nm and H = 400 nm.
Mentions: Since ϑ = 6° is a practically achievable value for SOI technology [9,17,18], parameters g = 120 nm, W = 155 nm and H = 400 nm are found to be the optimal choice, simultaneously achieving best fabrication tolerances with respect to sensitivity and single mode behavior. In fact, S = 0.92 has been calculated, showing a very low dependence with respect to both H and W. Then, practical advantages cannot be reached with an increase of W or H, without compromising the single mode behavior. On the other hand, this optimal choice guarantees a large tolerance for the silicon wires width, exhibiting a single mode behavior for W < 200 nm. This is a very important issue, due to the fact that W is dependent on both photo-lithography and etching processes, differently from the height of the slot waveguide. Figure 11(a–d) show the variation of both sensitivity and power confinement factor with respect to several technological parameters.

Bottom Line: In particular, we have focused on Silicon On Insulator (SOI) technology, representing the most popular technology for this kind of devices, simultaneously achieving high integration capabilities, small dimensions and low cost.An accurate analysis of single mode behavior for high aspect ratio slot waveguide has been also performed, in order to provide geometric limits for waveguide design purposes.Finally, the problem of coupling into a slot waveguide is addressed and a very compact and efficient slot coupler is proposed, whose geometry has been optimized to give a strip-slot-strip coupling efficiency close to 100%.

View Article: PubMed Central - PubMed

Affiliation: Dipartimento di Elettrotecnica ed Elettronica, Politecnico di Bari, Bari, Italy. passaro@deemail.poliba.it

ABSTRACT
Slot waveguides are becoming more and more attractive optical components, especially for chemical and bio-chemical sensing. In this paper an accurate analysis of slot waveguide fabrication tolerances is carried out, in order to find optimum design criteria for either homogeneous or absorption sensing mechanisms, in cases of low and high aspect ratio slot waveguides. In particular, we have focused on Silicon On Insulator (SOI) technology, representing the most popular technology for this kind of devices, simultaneously achieving high integration capabilities, small dimensions and low cost. An accurate analysis of single mode behavior for high aspect ratio slot waveguide has been also performed, in order to provide geometric limits for waveguide design purposes. Finally, the problem of coupling into a slot waveguide is addressed and a very compact and efficient slot coupler is proposed, whose geometry has been optimized to give a strip-slot-strip coupling efficiency close to 100%.

No MeSH data available.


Related in: MedlinePlus